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Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst
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Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst Abdolhamid Bamoniri a,∗, Bi Bi Fatemeh Mirjalili b, Sara Fouladgar a a b
Department of Organic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, Islamic Republic of Iran Department of Chemistry, College of Science, Yazd University, Yazd, Islamic Republic of Iran
a r t i c l e
i n f o
Article history: Received 9 August 2015 Revised 26 December 2015 Accepted 9 February 2016 Available online xxx Keywords: Ultrasonic irradiation SnCl4 -nano-SiO2 1,4-Dihydropyridine Multicomponent reaction Green chemistry
a b s t r a c t A simple and general synthetic method for the synthesis of 1,4-dihydropyridines via three- or fourcomponent condensation of aldehydes, 1,3-dicarbonyl compounds, and ammonium acetate was developed. In this procedure, nano-silica supported tin tetrachloride as an efficient solid acid catalyst was used under sonication condition. Short reaction times, excellent yields, simple work-up and reusability of catalyst are some advantages of this method. © 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
1. Introduction 1,4-dihydropyridines are an important class of nitrogen heterocycles. The most feasible position is 4th which exhibits various activities such as the calcium channel blockers or calcium antagonists [1]. Moreover, this compound emerged as one of the most important classes of drugs for the treatment angina pectoris, hypertension and other cardiovascular diseases [2,3]. The heterocyclic ring is the common feature for various pharmacological activities such as antihypertensive [4], antitumor [5], antiinflammatory activity [6], antitubercular activity [7], analgesic activity [8], antithrombotic and [9,10] also behave as neuroprotectants, cerebral antiischemic agents and chemosensitizers [5,11]. A recent analysis of the comprehensive medicinal chemistry database found that the dihydropyridine framework is the most prolific chemotypes [12]. Therefore, it is not surprising that 1,4-dihydropyridines have received increasing interest as synthetic targets and their synthesis remains an area of intense current interest to the chemical community [13–18]. Up till now, numerous literature citations exist relating to various attempts to improve the synthesis of these compounds [19–25]. Although most of these processes offer advantages, they suffer drawbacks such as longer reaction times, tedious work-up, unsatisfactory yields, the use of volatile organic solvents and the use of stoichiometric expensive reagents. Furthermore, the
∗
Corresponding author. Tel.: +98 31 55912384; fax: +98 31 55912397. E-mail address: [email protected], [email protected] (A. Bamoniri).
main drawbacks of existing methods are that the catalysts are destroyed in the work-up and cannot be recovered. Therefore, we prompted towards further investigation in the search for a better catalyst for the synthesis of 1,4-dihydropyridines, which will carry out the synthesis under simpler experimental set up reusability, economic viability and eco-friendly conditions. In recent years, the progress in the field of heterogeneous catalyst due to several advantages associated such as low cost, easy separation, recycling ability was occurred [26,27]. Tin tetrachloride (SnCl4 ) which is a powerful Lewis acid and a highly volatile, corrosive liquid is used as homogeneous catalyst in organic reactions [28–31]. When SnCl4 is grafted on the surface of silica, does not need special precautions for toxic and handling, or storage. Silicasupported SnCl4 is a mild solid Lewis acid, which promotes acid catalyzed organic reactions [32–34]. Silica-supported SnCl4 can be stored at ambient temperatures for months without losing its catalytic activity [35]. In this regard, nano-scale materials in modern organic chemistry exhibit higher activity and selectivity than their corresponding bulk materials due to theirs present high specific surface area of the active component. Our research group recently prepared nano-silica supported tin tetrachloride (SnCl4 nano-SiO2 ) as a nano catalyst in organic reactions [35,36]. Furthermore, the progress in the field of greener process which is based on sonochemistry has increasingly been considered as a simple, clean and convenient method in synthetic organic chemistry. Thus, chemists are focusing on its use for the synthesis of compounds [37–40]. Sonochemistry has advantages such as shorter reaction time, milder reaction condition, higher yield, improved selectivity
http://dx.doi.org/10.1016/j.jtice.2016.02.018 1876-1070/© 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Please cite this article as: A. Bamoniri et al., Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst, Journal of the Taiwan Institute of Chemical Engineers (2016), http://dx.doi.org/10.1016/j.jtice.2016.02.018
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and clean reaction in comparison to classical methods [41,42]. The use of ultrasound to promote chemical reaction is titled sonochemistry. Ultrasound irradiation offers energy source by acoustic cavitation phenomenon, which is a physical process that creates, enlarges and collapses gases in an irradiated liquid [43]. In this study, we report SnCl4 -nano-SiO2 promoted three or four components coupling reaction of aldehydes, 1,3-dicabonyl compounds, and ammonium acetate in ethanol under ultrasound irradiation (Scheme 1). This green method is a rapid ultrasonic assisted route for the synthesis of a wide variety of 1,4dihydropyridines. 2. Experimental 2.1. Chemicals and apparatus Chemicals were purchased from Merck company and used without further purification. Benzaldehyde was purified by distillation. Commercial nano silica gel (20 nm) was purchased from Sigma-Aldrich company. FT-IR spectra were run on a Nicolet Magna 550 spectrometer using KBr pellets. NMR spectra were recorded at 400 MHz (1 H) and 100 MHz (13 C) on a Bruker DRX-400 Avance spectrometer in CDCl3 as a solvent. A multiwave ultrasonic generator (Sonicator 30 0 0; Bandelin MS 72, Germany), equipped with a converter/transducer and titanium oscillator (horn), 12.5 mm in diameter, operating at 20 kHz with a maximum power output of 60 W, was used for the ultrasonic irradiation. The ultrasonic generator automatically adjusted the power level. Scanning electron microscopy (SEM) images of nano particles were determined with VEGA/TESCAN electron microscope. Transmission electron microscopy (TEM) photographs of nano particles were performed with a LEO 912 AB OMEGA instrument (Germany) with a LaB6 cathode and accelerating voltage of 100 kV. X-ray diffraction (XRD) patterns were recorded on a Philips Xpert MPD diffractometer equipped with a Cu Kα anode (λ = 1.54 A°) in the 2θ range from 5 to 80°. 2.2. Preparation of SnCl4 -nano-SiO2 SnCl4 (0.35 g, 0.16 ml, 1.34 mmol) was added dropwise to a mixture of CHCl3 (5 ml) and nano-silica gel (0.65 g). The resulting suspension was stirred for 1 h at room temperature. The reaction mixture was filtered, washed with chloroform, and dried at room temperature. SnCl4 -nano-SiO2 was obtained as a white powder which can be kept for several months in air at room temperature without losing its activity. 2.3. General procedure for the synthesis of 1,4-dihydropyridines 2.3.1. Typical reflux method (Method A) A mixture of aryl aldehydes (1 mmol), 1,3-dicarbonyl compounds (2 mmol), ammonium acetate (1.5 mmol) and SnCl4 -nanoSiO2 (30 mg) was refluxed in ethanol (5 ml) for the stipulated time mentioned in Table 3. The progress of the reaction was monitored by TLC (EtOAc:petroleum ether 7:3). After completion of the reaction, the hot mixture filtered to separate the catalyst. The heterogeneous catalyst was recovered by washing with CHCl3 and drying. The filtrate poured into crushed ice and obtained solid products, which recrystallized from ethanol to get pure crystalline dihydropyridines derivatives. 2.3.2. Ultrasound irradiation method (Method B) In a round-bottom flask, a mixture of aryl aldehydes (1 mmol), 1,3-dicarbonyl compounds (2 mmol), ammonium acetate (1.5 mmol) and SnCl4 -nano-SiO2 (20 mg) in ethanol (5 ml) was sonicated at 20 kHz frequency and 40 W power for the stipulated time
which was confirmed by TLC (EtOAc:petroleum ether 7:3). After completion of the reaction, the catalyst was separated by filtration. The filtrate poured into crushed ice and the solid product, which separated was filtered recrystallized from ethanol to get pure crystalline dihydropyridine derivatives. The heterogeneous catalyst was recovered by washing with CHCl3 and drying.
2.4. Spectral data for selected compounds 2,6-Dimethyl-4-phenyl-1,4-dihydropyridine-3,5diethylcarboxylate (4a) Yellowish solid, FT-IR (KBr, υ cm−1 ): 3342 (NH), 1689 (C=O, ester), 1487 (C=C, aromatic), 1212 (C-O). 1 H NMR (CDCl 3, 400 MH) δ : 7.28 (d, J = 7 Hz, 2H. Ar–H), 7.21 (t, J = 6.9 Hz, 2H. Ar–H), 7.13 (d, J = 6.9 Hz, 1H, Ar–H), 5.54 (s, 1H, NH), 4.99 (s, 1H, CH), 4.09 (q, J = 6.8 Hz, 4H, 2 OCH2 ), 2.34 (s, 6H, 2CH3 ), 1.22 (t, J = 6.8 Hz, 6H, 2CH3 CH2 ). 2,6-Dimethyl-4-(4-methoxyphenyl)-1,4-dihydropyridine-3,5diethylcarboxylate (4b) Yellow solid, FT-IR (KBr, υ cm−1 ): 3343 (NH), 1689 (C=O, ester), 1489 (C=C, aromatic), 1211 (C-O). 1 H NMR (CDCl3, 400 MH) δ : 7.20 (d, J = 7.9 Hz, 2H. Ar–H), 6.75 (d, J = 7.9 Hz, 2H, Ar–H), 5.54 (s, 1H, NH), 4.93 (s, 1H, CH), 4.10 (q, J = 7.4 Hz, 4H, 2 OCH2 ), 3.76 (s, 3H, OCH3 ), 2.33 (s, 6H, 2CH3 ), 1.23 (t, J = 7.4 Hz, 6H, 2CH3 CH2 ). 2,6-Dimethyl-4-(4-chlorophenyl)-1,4-dihydropyridine-3,5diethylcarboxylate (4c) Yellowish solid, FT-IR (KBr, υ cm−1 ): 3356 (NH), 1695 (C=O, ester), 1486 (C=C aromatic), 1214 (C-O), 1117 (C-Cl). 1 H NMR (CDCl3, 400 MH) δ : 7.22 (d, J = 8 Hz, 2H. Ar–H), 7.17 (d, J = 8 Hz, 2H, Ar–H), 5.55 (s, 1H, NH), 4.96 (s, 1H, CH), 4.08 (q, J = 7.2 Hz, 4H, 2 OCH2 ), 2.34 (s, 6H, 2CH3 ), 1.22 (t, J = 7.2 Hz, 6H, 2CH3 CH2 ) 2,6-Dimethyl-4-(4-nitrophenyl)-1,4-dihydropyridine-3,5diethylcarboxylate (4d) Colorless solid, FT-IR (KBr, υ cm−1 ): 3327 (N-H), 1696 (C=O, ester), 1517 (NO2 ), 1486 (C=C, aromatic), 1345 (NO2 ), 1213 (C-O); 1 H NMR (CDCl3, 400 MH) δ (ppm): 8.09 (d, J = 7.9 Hz, 2H, Ar–H), 7.45 (d, J = 7.9 Hz, 2H, Ar–H), 5.63 (s, 1H, NH), 5.10 (s, 1H, CH), 4.08 (q, J = 7.4 Hz, 4H, 2 OCH2 ), 2.37 (s, 6H, 2 CH3 ), 1.24 (t, J = 7.4 Hz, 6H, 2 CH3 CH2 ). 3,3,6,6-Tetramethyl-9-4-phenyl-3,4,6,7-tetrahydroacridine 1,8(2H,5H,9H,10H)-dione (4e) Yellowish solid, FT-IR (KBr, υ cm−1 ): 3279(NH), 1641 (C=O, dimedone), 1484 (C=C, aromatic). 1 H NMR (CDCl3 , 400 MHz) δ : 7.33 (d, J = 7.5 Hz, 2H, Ar–H), 7.19 (t, J = 7.5 Hz, 2H, Ar–H), 7.07 (t, J = 7.5 Hz, 1H, Ar–H), 6.68 (s, 1H, NH), 5.08 (s, 1H, CH), 2.14–2.39 (m, 8H, 4 CH2 ), 1.08 (s, 6H, 2 CH3 ), 0.97 (s, 6H, 2 CH3 ). 3,3,6,6-Tetramethyl-9-(4-methoxyphenyl)-3,4,6,7tetrahydroacridine-1,8 (2H,5H,9H,10H)-dione (4f) Yellow solid, FT-IR (KBr, υ cm−1 ) 3279 (NH), 1640 (C=O, dimedone), 1482 (C=C aromatic), 1224 (C-O); 1 H NMR (CDCl3 , 400 MHz) δ (ppm): 7.23 (d, J = 8.3 Hz, 2H, Ar–H), 6.72 (d, J = 8.3 Hz, 2H, Ar–H), 6.51 (s, 1H, NH), 5.02 (s, 1H, CH), 3.70 (s, 3H, OCH3 ), 2.14–2.37 (m, 8H, 4 CH2 ), 1.08 (s, 6H, 2 CH3 ), 0.96 (s, 6H, 2 CH3 ). 3,3,6,6-Tetramethyl-9-(4-chlorophenyl)-3,4,6,7tetrahydroacridine1,8(2H,5H,9H,10H)-dione (4 g) Yellow solid, FT-IR (KBr, υ cm−1 ) 3279 (NH) , 1644 (C=O, dimedone), 1486 (C=C, aromatic), 1145 (C-Cl). 1 H NMR (CDCl3 , 400 MHz) δ : 7.27 (d, J = 8 Hz, 2H, Ar–H), 7.17 (d, J = 8 Hz, 2H, Ar–H), 6.79 (s, 1H, NH), 5.05 (s, 1H, CH), 2.13–2.37 (m, 8H, 4 CH2 ), 1.08 (s, 6H, 2 CH3 ), 0.96 (s, 6H, 2 CH3 ). 3,3,6,6-Tetramethyl-9-(4-nitrophenyl)-3,4,6,7tetrahydroacridine-1,8(2H,5H,9H,10H)-dione (4 h) Yellow-orange solid, FT-IR (KBr, υ cm−1 ) 3384 (NH), 1643 (C=O, dimedone), 1514 (NO2 ), 1481 (C=C, aromatic), 1344 (NO2 ). 1 H NMR (CDCl3 , 400 MHz) δ : 8.07 (d, J = 8.3 Hz, 2H, Ar–H), 7.51(d, J = 8.3 Hz, 2H, Ar–H), 6.13 (s, 1H, NH), 5.15 (s, 1H, CH), 2.14–2.45 (m, 8H, 4 CH2 ), 1.10 (s, 6H, 2 CH3 ), 0.96 (s, 6H, 2 CH3 ).
Please cite this article as: A. Bamoniri et al., Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst, Journal of the Taiwan Institute of Chemical Engineers (2016), http://dx.doi.org/10.1016/j.jtice.2016.02.018
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2,7,7-Trimethyl-5-oxo-4-phenyl-1,4,5,6,7,8-hexahydroquinoline3-carboxylic acid ethyl ester (4i) Yellowish solid, FT-IR (KBr, υ cm−1 ): 3289 (NH), 1698 (C=O, ester), 1640 (C=O, dimedone), 1485 (C=C, aromatic), 1215 (C-O). 1 H NMR (CDCl3 , 400 MHz) δ : 7.30 (d, J = 7.5 Hz, 2H, Ar–H), 7.19 (t, J = 7.5 Hz, 2H, Ar–H), 7.09 (t, J = 7.2 Hz, 1H, Ar–H), 6.44 (s, 1H, NH), 5.05 (s, 1H, CH), 4.06 (q, J = 7.2 Hz, 2H, OCH2 ), 2.35 (s, 3H, CH3 ), 2.13–2.30 (m, 4H, 2 CH2 ), 1.18 (t, J =7.2 Hz, 3H, CH3 CH2 ), 1.07 (s, 3H, CH3 ), 0.93 (s, 3H, CH3 ). 2,7,7-Trimethyl-5-oxo-4-(4-methoxyphenyl)-1,4,5,6,7,8hexahydroquinoline-3-carboxylic acid ethyl ester (4j) Yellow solid, FT-IR (KBr, υ cm−1 ): 3279 (NH), 1700 (C=O, ester), 1645 (C=O, dimedone), 1497 (C=C, aromatic), 1217 (C-O). 1 H NMR (CDCl3 , 400 MHz) δ : 7.73 (d, J = 8 Hz, 2H, Ar–H), 7.10 (d, J = 8 Hz, 2H, Ar–H), 5.99 (s, 1H, NH), 4.99 (s, 1H, CH), 4.06 (q, J = 6.8 Hz, 2H, OCH2 ), 3.73 (s, 3H, OCH3 ), 2.36 (s, 3H, CH3 ), 2.13–2.34 (m, 4H, 2 CH2 ), 1.20 (t, J = 6.8 Hz, 3H, CH3 CH2 ), 1.07 (s, 3H, CH3 ), 0.94 (s, 3H, CH3 ). 2,7,7-Trimethyl-5-oxo-4-(4-chlorophenyl)-1,4,5,6,7,8hexahydroquinoline-3-carboxylic acid ethyl ester (4k) Yellow solid, FT-IR (KBr, υ cm−1 ): 3276 (NH), 1703 (C=O, ester), 1645 (C=O, dimedone), 1490 (C=C, aromatic), 1217 (C-O), 1158 (C-Cl). 1 H NMR (CDCl , 400 MHz) δ : 7.26 (d, J = 6.9 Hz, 2H, Ar–H), 7.16 (d, 3 J = 6.9 Hz, 2H, Ar–H), 6.00 (s, 1H, NH), 5.02 (s, 1H, CH), 4.06 (q, J = 6.8 Hz, 2H, OCH2 ), 2.38 (s, 3H, CH3 ), 2.13–2.31 (m, 4H, 2 CH2 ), 1.19 (t, J = 6.8 Hz, 3H, CH3 CH2 ), 1.08 (s, 3H, CH3 ), 0.93 (s, 3H, CH3 ). 2,7,7-Trimethyl-5-oxo-4-(4-nitrophenyl)-1,4,5,6,7,8hexahydroquinoline-3-carboxylic acid ethyl ester (4l) Yellow solid, FT-IR (KBr, υ cm−1 ): 3279 (NH), 1702 (C=O, ester), 1647 (C=O, dimedone), 1516 (NO2 ), 1344 (NO2 ); 1 H NMR (CDCl3 , 400 MHz) δ (ppm): 8.08 (d, J = 7.9 Hz, 2H, Ar–H), 7.48 (d, J = 7.9 Hz, 2H, Ar–H), 5.91 (s, 1H, NH), 5.15 (s, 1H, CH), 4.05 (q, J = 7.1 Hz, 2H, OCH2 ), 2.42 (s, 3H), 2.10–2.36 (m, 4H, 2 CH2 ), 1.17 (t, J = 7.1 Hz, 3H, CH3 CH2 ), 1.09 (s, 3H, CH3 ), 0.91 (s, 3H, CH3 ).
3
Cl
Cl Sn O O
O
Si
Si O O O O
Fig. 1. Suggested structure of SnCl4 -nano-SiO2 .
Fig. 2. FT-IR spectra of (a) nano-SiO2 , (b) SnCl4 -nano-SiO2 and (c) SnCl4 .
3. Results and discussion
The SEM images of nano silica and SnCl4 -nano-SiO2 exhibit nanocrystalline structures with a spherical shape (Fig. 4). The dimensions of nano-SiO2 and synthesized SnCl4 -nano-SiO2 were observed with TEM. The particle sizes of the nano-SiO2 and synthesized SnCl4 -nano-SiO2 were about 24 nm and 42 nm, respectively (Fig. 5).
3.1. Characterization of SnCl4 -nano-SiO2
3.2. Evaluation of the catalytic activity of SnCl4 -nano-SiO2
It is clear that, the kind of support can affect the properties of the supported catalyst. [44] It showed strong Lewis acidity when SiO2 used as support for SnCl4 and Lewis acid sites are the predominant acid species on the grafting SnCl4 catalysts. [45] Moreover, nanoparticles (NPs) exhibit the unique physical and chemical properties compared to bulk materials. Also, the nano SiO2 as a support increases contact surface of material to react quickly. So, we are going to apply SnCl4 -nano-SiO2 as an efficient acid catalyst. We have determined acidic capacity of this catalyst by titration because it produces HCl in water. We have found that 1 g of catalyst produced 3.24 mmol of H+ or Cl− . Also, for determination of the loading amounts of the Sn on the SnCl4 -nano-SiO2 by the addition of 10 ml aqueous solution of NaOH (0.2 M) to 1 g of catalyst and hot water. The remained silica gel has been isolated from the recovered Sn(OH)4 solution by filtration and the solution was evaporated to obtain a dry Sn(OH)4 powder. The calculated loading amount of Sn in the catalyst is 1.38 mmol g−1 . According to the above data, the possible structure of SnCl4 -nano-SiO2 is proposed as shown in Fig. 1. In the FT–IR spectrum of nano-SiO2 , the absorption bands for Si–OH and Si–O–Si appeared at 700 cm−1 and 1100 cm−1 , respectively. In SnCl4 -nano-SiO2 , in addition to the two absorption bands of nano-SiO2 , the O–Sn–Cl, was observed at 900 cm−1 (Fig. 2). Fig. 3 shows that the XRD patterns of nano-SiO2 and synthesized SnCl4 -nano-SiO2 . The broad peak at 22.27° relates to the amorphous nature of silica (Fig. 3a) and broad peak at 14.1121° shows that Sn is bonded to SiO2 and the proposed form of Si–O–Sn bonds (Fig. 3b).
To obtain appropriate conditions for the synthesis of 1,4dihydropyridines, different reaction conditions have been examined in the reaction of benzaldehyde, ethyl acetoacetate, dimedone and ammonium acetate as a model reaction (Scheme 2). We have investigated the effect of various solvents such as H2 O, EtOH, DMF, CH3 CN, and CHCl3 on a model reaction under ultrasound irradiation (20 kHz frequency and 40 W power). The results were summarized in Table 1. It was exhibited that ethanol was the best choice for the model reaction. Subsequently, in order to study the effects of SnCl4 -nano-SiO2 catalyst under ultrasound irradiation, catalytic behaviors of three types of catalyst were compared on the model reaction (Table 2). The obtained results showed that, in the absence of catalyst, no significant product was obtained and in the presence of SnCl4 nano-SiO2 the reaction was carried out in high yields (Entries 4– 8). Also the results in Table 2 exhibit the optimum amount of the catalyst was 20 mg (Entry 7). Notably, increasing of the catalyst did not show any significant changes in yield and time of reaction (Entry 8). In order to examine the role of ultrasound in this reaction, we have compared two methods A and B in Table 3. In all cases, when the reactions were carried out under ultrasound irradiation, times of reactions were shorter and the yields of the products were higher than reflux conditions. Also, used amount of catalyst were decreased under ultrasound irradiation. This should be explained based on the phenomenon of cavitation produced by ultrasound irradiation. Since ultrasound is generated in a probe, it will pass through a liquid, with the cycles exerting
Please cite this article as: A. Bamoniri et al., Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst, Journal of the Taiwan Institute of Chemical Engineers (2016), http://dx.doi.org/10.1016/j.jtice.2016.02.018
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Fig. 3. XRD patterns of (a) nano-SiO2 and (b) SnCl4 -nano-SiO2 .
Fig. 4. SEM images of (a) nano-SiO2 and (b) SnCl4 -nano-SiO2 .
Table 1 Optimization of the model reaction using various solvents under ultrasound irradiation. Entry
Solvent
Time (min)
Yield (%)a
1 2 3 4 5
CH3 CN CHCl3 DMF Water EtOH
5 5 5 5 5
77 73 86 83 96
a Isolated yields: benzaldehyde (1 mmol), ethyl acetoacetate (1 mmol), dimedone (1 mmol), ammonium acetate (1.5 mmol) and SnCl4 -nano-SiO2 (20 mg).
negative pressure on the liquid. If this negative pressure is strong enough, cavities or micro bubbles are formed. Cavitation is considered as a nucleated process, which will be formed at weak points in the liquid, such as gas-filled gaps in suspended particulate mat-
ter or micro bubbles from earlier cavitation events. Therefore, the presence of dispersed nano catalyst in solution during sonication provides nucleation sites for cavity formation over its surface. As micro bubbles are formed, they grow and implode. This process hit the surface with remarkable force and increase mass transfer of organic molecule between liquid and nano catalyst surface. This effect may improve the efficiency of the sonication method [43,46– 48]. Moreover this method, particularly when considering the basic green chemistry concepts, is more environmental friendly. As can be seen from the results in Table 3, aromatic aldehydes with various substituents carrying either electron-donating or electron-withdrawing groups reacted successfully with 1,3dicarbonyl compounds to afford the corresponding products in excellent yields. However, using dimedone instead of ethyl acetoacetate affected the yield and reaction time due to acidity of the methylene protons.
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5
Fig. 5. TEM images of (a) nano-SiO2 and (b) SnCl4 -nano-SiO2 .
O
O
+
ArCHO +
Ar
SnCl4-nano-SiO2 EtOH , U. S.
NH4OAc
O
O
N H
Scheme 1. One-pot synthesis of 1,4-dihydropyridines catalyzed by SnCl4 -nano-SiO2 under ultrasound irradiation.
O O
O
O
H
+
EtO
O
O
SnCl4-nano-SiO2
+
Ph
O
EtO
NH4OAc / EtOH
N H
Scheme 2. Standard model reaction.
OH H O H
H
NH3 ,
)))))
NH2
NH2
O
Ar
O Ar
O
O
O
O
Ar
O
O
)))))
O
Ar
O
O
Ar O
+
)))))
O
+
NH2
NH2 O
HO )))))
H2 O
: SnCl4-nano-SiO2 ))))) : Ultrasonic irradiaton
O
Ar
O
N H Scheme 3. Proposed mechanism for the synthesis of 1,4-dihydropyridines.
Please cite this article as: A. Bamoniri et al., Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst, Journal of the Taiwan Institute of Chemical Engineers (2016), http://dx.doi.org/10.1016/j.jtice.2016.02.018
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Table 2 Optimization of the model reaction using various catalysts under ultrasound irradiation. Entry
Catalyst (g)
Time (min)
Yield (%)a
1 2 3 4 5 6 7 8
None SnCl4 , 0.130 SnCl4 •SiO2 , 0.005 SnCl4 -nano-SiO2 , 0.005 SnCl4 -nano-SiO2 , 0.010 SnCl4 -nano-SiO2 , 0.015 SnCl4 -nano-SiO2 , 0.020 SnCl4 -nano-SiO2 , 0.030
10 10 8 8 5 5 5 5
Trace 65 63 84 89 91 96 96
Table 4 Comparison of some of the results obtained by the present method (ɪ) Fe3 O4 @SiO2 @PPh3 @[CrO3 Br] [54], (ɪɪ) nano-γ -Fe2 O3 [49], (ɪɪɪ) Zr(HPO4 )2 •H2 O [20]. Entry
Catalyst
Time (min)/yield (%) Products
1
ɪ
2
ɪɪ
3
ɪɪɪ
60/93 Table 3, Entry12 15/92 Table 3, Entry 3 120/96 Table 3, Entry 5
45/91 Table 3, Entry10 32/94 Table 3, Entry 4 – –
a Isolated yields: benzaldehyde (1 mmol), ethyl acetoacetate (1 mmol), dimedone (1 mmol) and ammonium acetate (1.5 mmol) in ethanol (5 ml).
The proposed mechanism for the formation of 1,4dihydropyridines in the presence of SnCl4 -nano-SiO2 , which can act as Lewis acid catalyst (empty π orbital of Sn in SnCl4 nano-SiO2 ) is depicted in Scheme 3. As can be seen, the acid–base interaction between SnCl4 -nanoSiO2 and lone pair electrons of oxygen in carbonyl bond causes the formation of corresponding Knoevenagel as well as enamine product. In the following, Michael addition is occurred between these intermediates for the formation of an open chain intermediate under ultrasonic irradiation [49]. The dipolar transition state (TS), that is undergo cyclohydration to furnish the desired products are accelerated better mass transport under ultrasonic irradiation by physical effects. Moreover, reaction in heterogeneous systems (solid–liquid) that proceed via ionic intermediate is influenced predominantly through the mechanical effects of cavitation. Table 4, compares our results with results reported by other groups in the synthesis of 1,4-dihydropyridine derivatives . It is important to note that, SnCl4 -nano-SiO2 acts as an effective catalyst with respect to reaction times and yields. In addition, Zr(HPO4 )2 •H2 O showed decreased in activity after two times while the recovered SnCl4 -nano-SiO2 was reused for four times without considerable loss of its activity. Consequently, it is essential for the solid acid to maintain strong acidity even after recycling and the most important benefit for
Fig. 6. Reusability study of SnCl4 -nano-SiO2 .
commercial applications. Thus, after the completion of the reaction, the reaction mixture was filter under hot condition to separate the catalyst. The recovered catalyst was washed with chloroform and was dried at room temperature without further purification to use for the next run of the current reaction under identical conditions. It was found that the catalyst could be reused for four times without any appreciable loss of its activity (Fig. 6). The XRD of the recovered nanocatalyst was shown in Fig. 7 and so there is no considerable change in its phase. Therefore, the
Table 3 Synthesis of 1,4-dihydropyridine derivatives under reflux conditions and sonication (methods A and B).
O ArCHO +
Entry
1 2 3 4 5 6 7 8 9 10 11 12 a b c
R
C6 H 5 4-MeOC6 H4 4-ClC6 H4 4-NO2 C6 H4 C6 H5 4-MeOC6 H4 4-ClC6 H4 4-NO2 C6 H4 C6 H5 4-MeOC6 H4 4-ClC6 H4 4-NO2 C6 H4
O
Method A
+
NH4OAc
O
Ar
O
SnCl4-nano-SiO2 / EtOH , reflux Method B SnCl4-nano-SiO2 / EtOH , U. S.
1,3-Dicarbonyls
Ethyl acetoacetate Ethyl acetoacetate Ethyl acetoacetate Ethyl acetoacetate Dimedone Dimedone Dimedone Dimedone Ethyl acetoacetate Ethyl acetoacetate Ethyl acetoacetate Ethyl acetoacetate
Product
Ethyl acetoacetate Ethyl acetoacetate Ethyl acetoacetate Ethyl acetoacetate Dimedone Dimedone Dimedone Dimedone Dimedone Dimedone Dimedone Dimedone
4a 4b 4c 4d 4e 4f 4g 4h 4i 4j 4k 4l
N H
.
Time (min)/yield (%)a
M. P. (°C)
Method A
Method B U.S.c
Found
Reported [Ref.]
b 25/92 20/89 25/94 20/90 25/90 15/94 15/92 18/95 15/95 15/89 20/96 20/95
7/96 6/93 5/95 5/97 4/95 4/94 4/98 3/98 5/96 6/94 5/95 4/98
157–160 160–162 145–147 130–132 189–191 269–271 297–299 285–287 225–227 258–260 245–246 240–242
158–160 [50] 161–163 [50] 147–148 [50] 129–131 [50] 190–192 [51] 270–272 [51] 299–230 [52] 286–288 [52] 228–229 [53] 260–262 [53] 245–246 [53] 241–242 [53]
Isolated yields: aryl aldehyde (1 mmol), 1,3-dicarbonyl compounds (2 mmol), ammonium acetate (1.5 mmol) in ethanol (5 ml). SnCl4 -nano-SiO2 (30 mg). SnCl4 -nano-SiO2 (20 mg).
Please cite this article as: A. Bamoniri et al., Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst, Journal of the Taiwan Institute of Chemical Engineers (2016), http://dx.doi.org/10.1016/j.jtice.2016.02.018
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7
Fig. 7. XRD patterns of recovered SnCl4 -nano-SiO2 after four recovery.
nanocatalyst is stable during synthesis of 1,4-dihydropyridine under ultrasound irradiation. 4. Conclusions In summary, we have developed a convenient, efficient method for the synthesis of 1,4-dihydropyridines via SnCl4 -nano-SiO2 as a highly efficient catalyst under ultrasound irradiation. This ultrasonically approach offers several advantages such as reducing reaction times, high yields, mild reaction conditions and operational simplicity. In addition, low cost, availability, recyclability and low toxicity of the catalyst make this methodology a valid contribution to the existing processes in the field of one-pot multicomponent Hantzsch reaction. Furthermore, the present procedure is readily amenable to parallel synthesis and generation of combinatorial dihydropyridines libraries. Acknowledgement The authors are grateful to University of Kashan for supporting this work by Grant No. (159189/32). Supplementary materials Supplementary material associated with this article can be found, in the online version, at doi:10.1016/j.jtice.2016.02.018. References [1] Triggle DJ. Calcium channel antagonists: clinical uses-past, present and future. Biochem Pharmacol 2007;74:1–9. [2] Eisenberg MJ, Brox A, Bestawros AN. Calcium channel blockers: an update. Am J Med 2004;116:35–43. [3] Bossert F, Meyer H, Wehinger E. 4-Aryldihydropyridines, a new class of highly active calcium antagonists. Angew Chem Int Ed in Engl 1981;20:762–9. [4] Loev B, Goodman MM, Snader KM, Tedeschi R, Macko E. Hantzsch-type dihydropyridine hypotensive agents. J Med Chem 1974;17:956–65. [5] Boer R, Gekeler V. Chemosensitizers in tumor therapy: new compounds promise better efficacy. Drug Future 1995;20:499–510. [6] Bahekar S, Shinde D. Synthesis and anti-inflammatory activity of 1,4dihydropyridines. Acta Pharmaceut 2002;52:281–7. [7] Wächter GA, Davis MC, Martin AR, Franzblau SG. Antimycobacterial activity of substituted isosteres of pyridine-and pyrazinecarboxylic acids. J Med Chem 1998;41:2436–8. [8] Gullapalli S, Ramarao P. L-type Ca 2+ channel modulation by dihydropyridines potentiates κ -opioid receptor agonist induced acute analgesia and inhibits development of tolerance in rats. Neuropharmacology 2002;42:467–75. [9] Sunkel CE, Fau de Casa-Juana M, Santos L, Mar Gomez M, Villarroya M, Gonzalez-Morales MA, Priego JG, Ortega MP. 4-Alkyl-1, 4-dihydropyridine derivatives as specific PAF-acether antagonists. J Med Chem 1990;33:3205–10.
[10] Handkinura MO. Effect of Ca +2 antagonist, vasodilators, diltizem, nifedipine, perhexiline and verapamil on platelet aggregation in vitro. Arzneim-Forsch Drug Res 1981;3:1131–4. [11] Klusa V. Cerebrocrast. Neuroprotectant, cognition enhancer. Drug Future 1995;20:135–8. [12] Sabakhi I. Study and Compraison catalysts that use in producing 1, 4dihydropyridine derivatives compounds. Life Sci J 2013;10:594–9. [13] Parthasarathy K, Jeganmohan M, Cheng CH. Rhodium-catalyzed one-pot synthesis of substituted pyridine derivatives from α , β -unsaturated ketoximes and alkynes. Org Lett 2008;10:325–8. [14] Movassaghi M, Hill MD, Ahmad OK. Direct synthesis of pyridine derivatives. J Am Chem Soc 20 07;129:10 096–7. [15] Movassaghi M, Hill MD. Synthesis of substituted pyridine derivatives via the ruthenium-catalyzed cycloisomerization of 3-azadienynes. J Am Chem Soc 2006;128:4592–3. [16] McCormick MM, Duong HA, Zuo G, Louie J. A nickel-catalyzed route to pyridines. J Am Chem Soc 2005;127:5030–1. [17] Colby DA, Bergman RG, Ellman JA. Rhodium-catalyzed C−C bond formation via heteroatom-directed C−H bond activation. Chem Rev 2010;110:624–55. [18] Barluenga J, Fernández-Rodríguez MÁ, García-García P, Aguilar E. Goldcatalyzed intermolecular hetero-dehydro-diels-alder cycloaddition of captodative dienynes with nitriles: A new reaction and regioselective direct access to pyridines. J Am Chem Soc 2008;130:2764–5. [19] Heravi MM, Bakhtiari K, Javadi NM, Bamoharram FF, Saeedi M, Oskooie HA. K7 [PW11CoO40]-catalyzed one-pot synthesis of polyhydroquinoline derivatives via the Hantzsch three component condensation. J Mol Catal A Chem 2007;264:50–2. [20] Abdolmohammadi S. α -ZrP: a highly efficient catalyst for solvent-free synthesis of pyrimido [5 ,4 :5,6] pyrido [2, 3-d] pyrimidinetetraone and 4arylacridinedione derivatives. Lett Org Chem 2014;11:465–9. [21] Ramesh K, Pasha M. Study on one-pot four-component synthesis of 9-aryl-hexahydro-acridine-1, 8-diones using SiO2 —I as a new heterogeneous catalyst and their anticancer activity. Bioorg Med Chem Lett 2014;24:3907–13. [22] Kumar A, Maurya RA. Efficient synthesis of Hantzsch esters and polyhydroquinoline derivatives in aqueous micelles. Synlett 2008:883–5. [23] Hong M, Cai C, Yi WB. Hafnium (IV) bis (perfluorooctanesulfonyl) imide complex catalyzed synthesis of polyhydroquinoline derivatives via unsymmetrical Hantzsch reaction in fluorous medium. J Fluorine Chem 2010;131:111–14. [24] Debache A, Boulcina R, Belfaitah A, Rhouati S, Carboni B. One-pot synthesis of 1, 4-dihydropyridines via a phenylboronic acid catalyzed Hantzsch threecomponent reaction. Synlet 2008:509–12. [25] Vahdat SM, Mardani HR, Golchoubian H, Khavarpour M, Baghery S, Roshankouhi Z. Cu(II) Schiff base as catalyst in the synthesis of 1,8dioxodecahydroacridine. Comb Chem High Throughput Screening 2013;16:2–6. [26] Singh NB, Singh RJ, Singh NP. Organic solid state reactivity. Tetrahedron 1994;50:6441–93. [27] Desiraju GR. Reactivity of organic solids—retrospect and prospect. Solid State Ionics 1997;101:839–42. [28] Bigdeli MA, Rahmati A, Abbasi-Ghadim H, Mahdavinia GH. SnCl4 and SbCl5 promoted aromatization of enamines. Tetrahedron Lett 2007;48:4575–8. [29] Kita Y, Matsuda S, Inoguchi R, Ganesh JK, Fujioka H. SnCl4 -promoted rearrangement of 2,3-epoxy alcohol derivatives: stereochemical control of the reaction. Tetrahedron Lett 2005;46:89–91. [30] Takeya T, Doi H, Ogata T, Okamoto I, Kotani E. Aerobic oxidative dimerization of 1-naphthols to 2,2 -binaphthoquinones mediated by SnCl4 and its application to natural product synthesis. Tetrahedron 2004;60:9049–60.
Please cite this article as: A. Bamoniri et al., Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst, Journal of the Taiwan Institute of Chemical Engineers (2016), http://dx.doi.org/10.1016/j.jtice.2016.02.018
JID: JTICE 8
ARTICLE IN PRESS
[m5G;February 29, 2016;9:17]
A. Bamoniri et al. / Journal of the Taiwan Institute of Chemical Engineers 000 (2016) 1–8
[31] Dubost C, Leroy B, IE M, Tinant B, Declercq JP, Bryans J. Stereoselective synthesis of functionalised triol units by SnCl4 promoted allylation of α benzyloxyaldehydes: crucial role of the stoichiometry of the Lewis acid. Tetrahedron 2004;60:7693–704. [32] Li YQ, Cheng LH. A rapid and convenient synthesis of acylals from aldehydes and acetic anhydrides catalyzed by SnCl4 /SiO2 . Chin Chem Lett 2001;12:565–8. [33] Mirjalili BBF, Hashemi MM, Sadeghi B, Emtiazi H. SnCl4 /SiO2 : an efficient heterogeneous alternative for one-pot synthesis of β -acetamidoketones. J Chin Chem Soc 2009;56:386–91. [34] Niknam K, Zolfigol MA, Saberi D, Molaee H. Preparation of silica supported tin chloride: as a recyclable catalyst for the silylation of hydroxyl groups with HMDS. J Chin Chem Soc 2009;56:1257–64. [35] Mirjalili BF, Bamoniri A, Mirhoseini MA. Nano-SnCl4 •SiO2 –a versatile and efficient catalyst for synthesis of 14-aryl-or 14-alkyl-14H-dibenzo [a, j] xanthenes. Chem Heterocycl Compd 2012;48:856–60. [36] Mirjalili BF, Bamoniri A, Mirhoseini MA. Nano-SnCl4 -SiO2 : an efficient catalyst for one-pot synthesis of 2, 4, 5-tri substituted imidazoles under solvent-free conditions. Scientia Iranica 2013;20:587–91. [37] Cravotto G, Cintas P. Power ultrasound in organic synthesis: moving cavitational chemistry from academia to innovative and large-scale applications. Chem Soc Rev 2006;35:180–96. [38] Safari J, Banitaba SH, Dehghan-Khalili S. Ultrasound-promoted an efficient method for one-pot synthesis of 2-amino-4, 6-diphenylnicotinonitriles in water: a rapid procedure without catalyst. Ultrason Sonochem 2012;19:1061–9. [39] Banitaba SH, Safari J, Deghan-Khalili S. Ultrasound promoted one-pot synthesis of 2-amino-4, 8-dihydropyrano [3, 2-b] pyran-3-carbonitrile scaffolds in aqueous media: a complementary green chemistrytool to organic synthesis. Ultrason Sonochem 2013;20:401–7. [40] Moshtael-Arani N, Safari J. A rapid and efficient ultrasound-assisted synthesis of 5, 5-diphenylhydantoins and 5, 5-diphenyl-2-thiohydantoins. Ultrason Sonochem 2011;18:640–3. [41] Khaligh NG, Shirini F. Introduction of poly (4-vinylpyridinium) perchlorate as a new, efficient, and versatile solid acid catalyst for one-pot synthesis of substituted coumarins under ultrasonic irradiation. Ultrason Sonochem 2013;20:26– 31. [42] Khaligh NG. Ultrasound assisted the chemoselective 1, 1-diacetate protection and deprotection of aldehydes catalyzed by poly (4-vinylpyridinium) hydrogen sulfate salt as a eco-benign, efficient and reusable solid acid catalyst. Ultrason Sonochem 2013;20:19–25.
[43] Nagargoje D, Mandhane P, Shingote S, Badadhe P, Gill C. Ultrasound assisted one pot synthesis of imidazole derivatives using diethyl bromophosphate as an oxidant. Ultrason Sonochem 2012;19:94–6. [44] Burger K. Capillary mössbauer spectroscopy (CMS)—a new method for the study of liquids fixed in a suitable carrier. Spectrochim Acta A Mol Spectro 1987;43:1105–10. [45] Ji M, Li X, Wang J, Zhu J, Zhou L. Grafting SnCl4 catalyst as a novel solid acid for the synthesis of 3-methylbut-3-en-1-ol. Catal Today 2011;173:28–31. [46] Wang X, Wei Y, Wang J, Guo W, Wang C. The kinetics and mechanism of ultrasonic degradation of p-nitrophenol in aqueous solution with CCl4 enhancement. Ultrason Sonochem 2012;19:32–7. [47] Gunasekaran P, Perumal S, Yogeeswari P, Sriram D. A facile four-component sequential protocol in the expedient synthesis of novel 2-aryl-5-methyl-2, 3dihydro-1H-3-pyrazolones in water and their antitubercular evaluation. Eur J Med Chem 2011;46:4530–6. [48] Cella R, Stefani HA. Ultrasound in heterocycles chemistry. Tetrahedron 2009;65:2619–41. [49] Kolvari E, Zolfigol M, Koukabi N, Shirmardi-Shaghasemi B. A simple and efficient one-pot synthesis of Hantzsch 1, 4-dihydropyridines using silica sulphuric acid as a heterogeneous and reusable catalyst under solvent-free conditions. Chem Pap 2011;65:898–902. [50] Vanden Eynde JJ, Delfosse F, Mayence A, Van Haverbeke Y. Old reagents, new results: Aromatization of Hantzsch 1, 4-dihydropyridines with manganese dioxide and 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone. Tetrahedron 1995;51:6511–16. [51] Nazario Martin MQ, Seoane C, Soto JL, Mora A, Suarez M, Ochoa E, Morales A, Del Bosque JR. Synthesis and conformational study of acridine derivatives related to 1,4-dihydropyridines. J Heterocyclic Chem 1995;32:235–8. [52] Balalaie S, Chadegani F, Darviche F, Bijanzadeh HR. One-pot synthesis of 1, 8-dioxo-decahydroacridine derivatives in aqueous media. Chin J Chem 2009;27:1953–6. [53] Bandgar B, More P, Kamble V, Totre J. Synthesis of polyhydroquinoline derivatives under aqueous media. Arkivoc 2008:1–8. [54] Maleki A, Rahimi R, Maleki S, Hamidi N. Synthesis and characterization of magnetic bromochromate hybrid nanomaterials with triphenylphosphine surface-modified iron oxide nanoparticles and their catalytic application in multicomponent reactions. RSC Adv 2014;4:29765–71.
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Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst Abdolhamid Bamoniri a,∗, Bi Bi Fatemeh Mirjalili b, Sara Fouladgar a a b
Department of Organic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, Islamic Republic of Iran Department of Chemistry, College of Science, Yazd University, Yazd, Islamic Republic of Iran
a r t i c l e
i n f o
Article history: Received 9 August 2015 Revised 26 December 2015 Accepted 9 February 2016 Available online xxx Keywords: Ultrasonic irradiation SnCl4 -nano-SiO2 1,4-Dihydropyridine Multicomponent reaction Green chemistry
a b s t r a c t A simple and general synthetic method for the synthesis of 1,4-dihydropyridines via three- or fourcomponent condensation of aldehydes, 1,3-dicarbonyl compounds, and ammonium acetate was developed. In this procedure, nano-silica supported tin tetrachloride as an efficient solid acid catalyst was used under sonication condition. Short reaction times, excellent yields, simple work-up and reusability of catalyst are some advantages of this method. © 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
1. Introduction 1,4-dihydropyridines are an important class of nitrogen heterocycles. The most feasible position is 4th which exhibits various activities such as the calcium channel blockers or calcium antagonists [1]. Moreover, this compound emerged as one of the most important classes of drugs for the treatment angina pectoris, hypertension and other cardiovascular diseases [2,3]. The heterocyclic ring is the common feature for various pharmacological activities such as antihypertensive [4], antitumor [5], antiinflammatory activity [6], antitubercular activity [7], analgesic activity [8], antithrombotic and [9,10] also behave as neuroprotectants, cerebral antiischemic agents and chemosensitizers [5,11]. A recent analysis of the comprehensive medicinal chemistry database found that the dihydropyridine framework is the most prolific chemotypes [12]. Therefore, it is not surprising that 1,4-dihydropyridines have received increasing interest as synthetic targets and their synthesis remains an area of intense current interest to the chemical community [13–18]. Up till now, numerous literature citations exist relating to various attempts to improve the synthesis of these compounds [19–25]. Although most of these processes offer advantages, they suffer drawbacks such as longer reaction times, tedious work-up, unsatisfactory yields, the use of volatile organic solvents and the use of stoichiometric expensive reagents. Furthermore, the
∗
Corresponding author. Tel.: +98 31 55912384; fax: +98 31 55912397. E-mail address: [email protected], [email protected] (A. Bamoniri).
main drawbacks of existing methods are that the catalysts are destroyed in the work-up and cannot be recovered. Therefore, we prompted towards further investigation in the search for a better catalyst for the synthesis of 1,4-dihydropyridines, which will carry out the synthesis under simpler experimental set up reusability, economic viability and eco-friendly conditions. In recent years, the progress in the field of heterogeneous catalyst due to several advantages associated such as low cost, easy separation, recycling ability was occurred [26,27]. Tin tetrachloride (SnCl4 ) which is a powerful Lewis acid and a highly volatile, corrosive liquid is used as homogeneous catalyst in organic reactions [28–31]. When SnCl4 is grafted on the surface of silica, does not need special precautions for toxic and handling, or storage. Silicasupported SnCl4 is a mild solid Lewis acid, which promotes acid catalyzed organic reactions [32–34]. Silica-supported SnCl4 can be stored at ambient temperatures for months without losing its catalytic activity [35]. In this regard, nano-scale materials in modern organic chemistry exhibit higher activity and selectivity than their corresponding bulk materials due to theirs present high specific surface area of the active component. Our research group recently prepared nano-silica supported tin tetrachloride (SnCl4 nano-SiO2 ) as a nano catalyst in organic reactions [35,36]. Furthermore, the progress in the field of greener process which is based on sonochemistry has increasingly been considered as a simple, clean and convenient method in synthetic organic chemistry. Thus, chemists are focusing on its use for the synthesis of compounds [37–40]. Sonochemistry has advantages such as shorter reaction time, milder reaction condition, higher yield, improved selectivity
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and clean reaction in comparison to classical methods [41,42]. The use of ultrasound to promote chemical reaction is titled sonochemistry. Ultrasound irradiation offers energy source by acoustic cavitation phenomenon, which is a physical process that creates, enlarges and collapses gases in an irradiated liquid [43]. In this study, we report SnCl4 -nano-SiO2 promoted three or four components coupling reaction of aldehydes, 1,3-dicabonyl compounds, and ammonium acetate in ethanol under ultrasound irradiation (Scheme 1). This green method is a rapid ultrasonic assisted route for the synthesis of a wide variety of 1,4dihydropyridines. 2. Experimental 2.1. Chemicals and apparatus Chemicals were purchased from Merck company and used without further purification. Benzaldehyde was purified by distillation. Commercial nano silica gel (20 nm) was purchased from Sigma-Aldrich company. FT-IR spectra were run on a Nicolet Magna 550 spectrometer using KBr pellets. NMR spectra were recorded at 400 MHz (1 H) and 100 MHz (13 C) on a Bruker DRX-400 Avance spectrometer in CDCl3 as a solvent. A multiwave ultrasonic generator (Sonicator 30 0 0; Bandelin MS 72, Germany), equipped with a converter/transducer and titanium oscillator (horn), 12.5 mm in diameter, operating at 20 kHz with a maximum power output of 60 W, was used for the ultrasonic irradiation. The ultrasonic generator automatically adjusted the power level. Scanning electron microscopy (SEM) images of nano particles were determined with VEGA/TESCAN electron microscope. Transmission electron microscopy (TEM) photographs of nano particles were performed with a LEO 912 AB OMEGA instrument (Germany) with a LaB6 cathode and accelerating voltage of 100 kV. X-ray diffraction (XRD) patterns were recorded on a Philips Xpert MPD diffractometer equipped with a Cu Kα anode (λ = 1.54 A°) in the 2θ range from 5 to 80°. 2.2. Preparation of SnCl4 -nano-SiO2 SnCl4 (0.35 g, 0.16 ml, 1.34 mmol) was added dropwise to a mixture of CHCl3 (5 ml) and nano-silica gel (0.65 g). The resulting suspension was stirred for 1 h at room temperature. The reaction mixture was filtered, washed with chloroform, and dried at room temperature. SnCl4 -nano-SiO2 was obtained as a white powder which can be kept for several months in air at room temperature without losing its activity. 2.3. General procedure for the synthesis of 1,4-dihydropyridines 2.3.1. Typical reflux method (Method A) A mixture of aryl aldehydes (1 mmol), 1,3-dicarbonyl compounds (2 mmol), ammonium acetate (1.5 mmol) and SnCl4 -nanoSiO2 (30 mg) was refluxed in ethanol (5 ml) for the stipulated time mentioned in Table 3. The progress of the reaction was monitored by TLC (EtOAc:petroleum ether 7:3). After completion of the reaction, the hot mixture filtered to separate the catalyst. The heterogeneous catalyst was recovered by washing with CHCl3 and drying. The filtrate poured into crushed ice and obtained solid products, which recrystallized from ethanol to get pure crystalline dihydropyridines derivatives. 2.3.2. Ultrasound irradiation method (Method B) In a round-bottom flask, a mixture of aryl aldehydes (1 mmol), 1,3-dicarbonyl compounds (2 mmol), ammonium acetate (1.5 mmol) and SnCl4 -nano-SiO2 (20 mg) in ethanol (5 ml) was sonicated at 20 kHz frequency and 40 W power for the stipulated time
which was confirmed by TLC (EtOAc:petroleum ether 7:3). After completion of the reaction, the catalyst was separated by filtration. The filtrate poured into crushed ice and the solid product, which separated was filtered recrystallized from ethanol to get pure crystalline dihydropyridine derivatives. The heterogeneous catalyst was recovered by washing with CHCl3 and drying.
2.4. Spectral data for selected compounds 2,6-Dimethyl-4-phenyl-1,4-dihydropyridine-3,5diethylcarboxylate (4a) Yellowish solid, FT-IR (KBr, υ cm−1 ): 3342 (NH), 1689 (C=O, ester), 1487 (C=C, aromatic), 1212 (C-O). 1 H NMR (CDCl 3, 400 MH) δ : 7.28 (d, J = 7 Hz, 2H. Ar–H), 7.21 (t, J = 6.9 Hz, 2H. Ar–H), 7.13 (d, J = 6.9 Hz, 1H, Ar–H), 5.54 (s, 1H, NH), 4.99 (s, 1H, CH), 4.09 (q, J = 6.8 Hz, 4H, 2 OCH2 ), 2.34 (s, 6H, 2CH3 ), 1.22 (t, J = 6.8 Hz, 6H, 2CH3 CH2 ). 2,6-Dimethyl-4-(4-methoxyphenyl)-1,4-dihydropyridine-3,5diethylcarboxylate (4b) Yellow solid, FT-IR (KBr, υ cm−1 ): 3343 (NH), 1689 (C=O, ester), 1489 (C=C, aromatic), 1211 (C-O). 1 H NMR (CDCl3, 400 MH) δ : 7.20 (d, J = 7.9 Hz, 2H. Ar–H), 6.75 (d, J = 7.9 Hz, 2H, Ar–H), 5.54 (s, 1H, NH), 4.93 (s, 1H, CH), 4.10 (q, J = 7.4 Hz, 4H, 2 OCH2 ), 3.76 (s, 3H, OCH3 ), 2.33 (s, 6H, 2CH3 ), 1.23 (t, J = 7.4 Hz, 6H, 2CH3 CH2 ). 2,6-Dimethyl-4-(4-chlorophenyl)-1,4-dihydropyridine-3,5diethylcarboxylate (4c) Yellowish solid, FT-IR (KBr, υ cm−1 ): 3356 (NH), 1695 (C=O, ester), 1486 (C=C aromatic), 1214 (C-O), 1117 (C-Cl). 1 H NMR (CDCl3, 400 MH) δ : 7.22 (d, J = 8 Hz, 2H. Ar–H), 7.17 (d, J = 8 Hz, 2H, Ar–H), 5.55 (s, 1H, NH), 4.96 (s, 1H, CH), 4.08 (q, J = 7.2 Hz, 4H, 2 OCH2 ), 2.34 (s, 6H, 2CH3 ), 1.22 (t, J = 7.2 Hz, 6H, 2CH3 CH2 ) 2,6-Dimethyl-4-(4-nitrophenyl)-1,4-dihydropyridine-3,5diethylcarboxylate (4d) Colorless solid, FT-IR (KBr, υ cm−1 ): 3327 (N-H), 1696 (C=O, ester), 1517 (NO2 ), 1486 (C=C, aromatic), 1345 (NO2 ), 1213 (C-O); 1 H NMR (CDCl3, 400 MH) δ (ppm): 8.09 (d, J = 7.9 Hz, 2H, Ar–H), 7.45 (d, J = 7.9 Hz, 2H, Ar–H), 5.63 (s, 1H, NH), 5.10 (s, 1H, CH), 4.08 (q, J = 7.4 Hz, 4H, 2 OCH2 ), 2.37 (s, 6H, 2 CH3 ), 1.24 (t, J = 7.4 Hz, 6H, 2 CH3 CH2 ). 3,3,6,6-Tetramethyl-9-4-phenyl-3,4,6,7-tetrahydroacridine 1,8(2H,5H,9H,10H)-dione (4e) Yellowish solid, FT-IR (KBr, υ cm−1 ): 3279(NH), 1641 (C=O, dimedone), 1484 (C=C, aromatic). 1 H NMR (CDCl3 , 400 MHz) δ : 7.33 (d, J = 7.5 Hz, 2H, Ar–H), 7.19 (t, J = 7.5 Hz, 2H, Ar–H), 7.07 (t, J = 7.5 Hz, 1H, Ar–H), 6.68 (s, 1H, NH), 5.08 (s, 1H, CH), 2.14–2.39 (m, 8H, 4 CH2 ), 1.08 (s, 6H, 2 CH3 ), 0.97 (s, 6H, 2 CH3 ). 3,3,6,6-Tetramethyl-9-(4-methoxyphenyl)-3,4,6,7tetrahydroacridine-1,8 (2H,5H,9H,10H)-dione (4f) Yellow solid, FT-IR (KBr, υ cm−1 ) 3279 (NH), 1640 (C=O, dimedone), 1482 (C=C aromatic), 1224 (C-O); 1 H NMR (CDCl3 , 400 MHz) δ (ppm): 7.23 (d, J = 8.3 Hz, 2H, Ar–H), 6.72 (d, J = 8.3 Hz, 2H, Ar–H), 6.51 (s, 1H, NH), 5.02 (s, 1H, CH), 3.70 (s, 3H, OCH3 ), 2.14–2.37 (m, 8H, 4 CH2 ), 1.08 (s, 6H, 2 CH3 ), 0.96 (s, 6H, 2 CH3 ). 3,3,6,6-Tetramethyl-9-(4-chlorophenyl)-3,4,6,7tetrahydroacridine1,8(2H,5H,9H,10H)-dione (4 g) Yellow solid, FT-IR (KBr, υ cm−1 ) 3279 (NH) , 1644 (C=O, dimedone), 1486 (C=C, aromatic), 1145 (C-Cl). 1 H NMR (CDCl3 , 400 MHz) δ : 7.27 (d, J = 8 Hz, 2H, Ar–H), 7.17 (d, J = 8 Hz, 2H, Ar–H), 6.79 (s, 1H, NH), 5.05 (s, 1H, CH), 2.13–2.37 (m, 8H, 4 CH2 ), 1.08 (s, 6H, 2 CH3 ), 0.96 (s, 6H, 2 CH3 ). 3,3,6,6-Tetramethyl-9-(4-nitrophenyl)-3,4,6,7tetrahydroacridine-1,8(2H,5H,9H,10H)-dione (4 h) Yellow-orange solid, FT-IR (KBr, υ cm−1 ) 3384 (NH), 1643 (C=O, dimedone), 1514 (NO2 ), 1481 (C=C, aromatic), 1344 (NO2 ). 1 H NMR (CDCl3 , 400 MHz) δ : 8.07 (d, J = 8.3 Hz, 2H, Ar–H), 7.51(d, J = 8.3 Hz, 2H, Ar–H), 6.13 (s, 1H, NH), 5.15 (s, 1H, CH), 2.14–2.45 (m, 8H, 4 CH2 ), 1.10 (s, 6H, 2 CH3 ), 0.96 (s, 6H, 2 CH3 ).
Please cite this article as: A. Bamoniri et al., Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst, Journal of the Taiwan Institute of Chemical Engineers (2016), http://dx.doi.org/10.1016/j.jtice.2016.02.018
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2,7,7-Trimethyl-5-oxo-4-phenyl-1,4,5,6,7,8-hexahydroquinoline3-carboxylic acid ethyl ester (4i) Yellowish solid, FT-IR (KBr, υ cm−1 ): 3289 (NH), 1698 (C=O, ester), 1640 (C=O, dimedone), 1485 (C=C, aromatic), 1215 (C-O). 1 H NMR (CDCl3 , 400 MHz) δ : 7.30 (d, J = 7.5 Hz, 2H, Ar–H), 7.19 (t, J = 7.5 Hz, 2H, Ar–H), 7.09 (t, J = 7.2 Hz, 1H, Ar–H), 6.44 (s, 1H, NH), 5.05 (s, 1H, CH), 4.06 (q, J = 7.2 Hz, 2H, OCH2 ), 2.35 (s, 3H, CH3 ), 2.13–2.30 (m, 4H, 2 CH2 ), 1.18 (t, J =7.2 Hz, 3H, CH3 CH2 ), 1.07 (s, 3H, CH3 ), 0.93 (s, 3H, CH3 ). 2,7,7-Trimethyl-5-oxo-4-(4-methoxyphenyl)-1,4,5,6,7,8hexahydroquinoline-3-carboxylic acid ethyl ester (4j) Yellow solid, FT-IR (KBr, υ cm−1 ): 3279 (NH), 1700 (C=O, ester), 1645 (C=O, dimedone), 1497 (C=C, aromatic), 1217 (C-O). 1 H NMR (CDCl3 , 400 MHz) δ : 7.73 (d, J = 8 Hz, 2H, Ar–H), 7.10 (d, J = 8 Hz, 2H, Ar–H), 5.99 (s, 1H, NH), 4.99 (s, 1H, CH), 4.06 (q, J = 6.8 Hz, 2H, OCH2 ), 3.73 (s, 3H, OCH3 ), 2.36 (s, 3H, CH3 ), 2.13–2.34 (m, 4H, 2 CH2 ), 1.20 (t, J = 6.8 Hz, 3H, CH3 CH2 ), 1.07 (s, 3H, CH3 ), 0.94 (s, 3H, CH3 ). 2,7,7-Trimethyl-5-oxo-4-(4-chlorophenyl)-1,4,5,6,7,8hexahydroquinoline-3-carboxylic acid ethyl ester (4k) Yellow solid, FT-IR (KBr, υ cm−1 ): 3276 (NH), 1703 (C=O, ester), 1645 (C=O, dimedone), 1490 (C=C, aromatic), 1217 (C-O), 1158 (C-Cl). 1 H NMR (CDCl , 400 MHz) δ : 7.26 (d, J = 6.9 Hz, 2H, Ar–H), 7.16 (d, 3 J = 6.9 Hz, 2H, Ar–H), 6.00 (s, 1H, NH), 5.02 (s, 1H, CH), 4.06 (q, J = 6.8 Hz, 2H, OCH2 ), 2.38 (s, 3H, CH3 ), 2.13–2.31 (m, 4H, 2 CH2 ), 1.19 (t, J = 6.8 Hz, 3H, CH3 CH2 ), 1.08 (s, 3H, CH3 ), 0.93 (s, 3H, CH3 ). 2,7,7-Trimethyl-5-oxo-4-(4-nitrophenyl)-1,4,5,6,7,8hexahydroquinoline-3-carboxylic acid ethyl ester (4l) Yellow solid, FT-IR (KBr, υ cm−1 ): 3279 (NH), 1702 (C=O, ester), 1647 (C=O, dimedone), 1516 (NO2 ), 1344 (NO2 ); 1 H NMR (CDCl3 , 400 MHz) δ (ppm): 8.08 (d, J = 7.9 Hz, 2H, Ar–H), 7.48 (d, J = 7.9 Hz, 2H, Ar–H), 5.91 (s, 1H, NH), 5.15 (s, 1H, CH), 4.05 (q, J = 7.1 Hz, 2H, OCH2 ), 2.42 (s, 3H), 2.10–2.36 (m, 4H, 2 CH2 ), 1.17 (t, J = 7.1 Hz, 3H, CH3 CH2 ), 1.09 (s, 3H, CH3 ), 0.91 (s, 3H, CH3 ).
3
Cl
Cl Sn O O
O
Si
Si O O O O
Fig. 1. Suggested structure of SnCl4 -nano-SiO2 .
Fig. 2. FT-IR spectra of (a) nano-SiO2 , (b) SnCl4 -nano-SiO2 and (c) SnCl4 .
3. Results and discussion
The SEM images of nano silica and SnCl4 -nano-SiO2 exhibit nanocrystalline structures with a spherical shape (Fig. 4). The dimensions of nano-SiO2 and synthesized SnCl4 -nano-SiO2 were observed with TEM. The particle sizes of the nano-SiO2 and synthesized SnCl4 -nano-SiO2 were about 24 nm and 42 nm, respectively (Fig. 5).
3.1. Characterization of SnCl4 -nano-SiO2
3.2. Evaluation of the catalytic activity of SnCl4 -nano-SiO2
It is clear that, the kind of support can affect the properties of the supported catalyst. [44] It showed strong Lewis acidity when SiO2 used as support for SnCl4 and Lewis acid sites are the predominant acid species on the grafting SnCl4 catalysts. [45] Moreover, nanoparticles (NPs) exhibit the unique physical and chemical properties compared to bulk materials. Also, the nano SiO2 as a support increases contact surface of material to react quickly. So, we are going to apply SnCl4 -nano-SiO2 as an efficient acid catalyst. We have determined acidic capacity of this catalyst by titration because it produces HCl in water. We have found that 1 g of catalyst produced 3.24 mmol of H+ or Cl− . Also, for determination of the loading amounts of the Sn on the SnCl4 -nano-SiO2 by the addition of 10 ml aqueous solution of NaOH (0.2 M) to 1 g of catalyst and hot water. The remained silica gel has been isolated from the recovered Sn(OH)4 solution by filtration and the solution was evaporated to obtain a dry Sn(OH)4 powder. The calculated loading amount of Sn in the catalyst is 1.38 mmol g−1 . According to the above data, the possible structure of SnCl4 -nano-SiO2 is proposed as shown in Fig. 1. In the FT–IR spectrum of nano-SiO2 , the absorption bands for Si–OH and Si–O–Si appeared at 700 cm−1 and 1100 cm−1 , respectively. In SnCl4 -nano-SiO2 , in addition to the two absorption bands of nano-SiO2 , the O–Sn–Cl, was observed at 900 cm−1 (Fig. 2). Fig. 3 shows that the XRD patterns of nano-SiO2 and synthesized SnCl4 -nano-SiO2 . The broad peak at 22.27° relates to the amorphous nature of silica (Fig. 3a) and broad peak at 14.1121° shows that Sn is bonded to SiO2 and the proposed form of Si–O–Sn bonds (Fig. 3b).
To obtain appropriate conditions for the synthesis of 1,4dihydropyridines, different reaction conditions have been examined in the reaction of benzaldehyde, ethyl acetoacetate, dimedone and ammonium acetate as a model reaction (Scheme 2). We have investigated the effect of various solvents such as H2 O, EtOH, DMF, CH3 CN, and CHCl3 on a model reaction under ultrasound irradiation (20 kHz frequency and 40 W power). The results were summarized in Table 1. It was exhibited that ethanol was the best choice for the model reaction. Subsequently, in order to study the effects of SnCl4 -nano-SiO2 catalyst under ultrasound irradiation, catalytic behaviors of three types of catalyst were compared on the model reaction (Table 2). The obtained results showed that, in the absence of catalyst, no significant product was obtained and in the presence of SnCl4 nano-SiO2 the reaction was carried out in high yields (Entries 4– 8). Also the results in Table 2 exhibit the optimum amount of the catalyst was 20 mg (Entry 7). Notably, increasing of the catalyst did not show any significant changes in yield and time of reaction (Entry 8). In order to examine the role of ultrasound in this reaction, we have compared two methods A and B in Table 3. In all cases, when the reactions were carried out under ultrasound irradiation, times of reactions were shorter and the yields of the products were higher than reflux conditions. Also, used amount of catalyst were decreased under ultrasound irradiation. This should be explained based on the phenomenon of cavitation produced by ultrasound irradiation. Since ultrasound is generated in a probe, it will pass through a liquid, with the cycles exerting
Please cite this article as: A. Bamoniri et al., Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst, Journal of the Taiwan Institute of Chemical Engineers (2016), http://dx.doi.org/10.1016/j.jtice.2016.02.018
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Fig. 3. XRD patterns of (a) nano-SiO2 and (b) SnCl4 -nano-SiO2 .
Fig. 4. SEM images of (a) nano-SiO2 and (b) SnCl4 -nano-SiO2 .
Table 1 Optimization of the model reaction using various solvents under ultrasound irradiation. Entry
Solvent
Time (min)
Yield (%)a
1 2 3 4 5
CH3 CN CHCl3 DMF Water EtOH
5 5 5 5 5
77 73 86 83 96
a Isolated yields: benzaldehyde (1 mmol), ethyl acetoacetate (1 mmol), dimedone (1 mmol), ammonium acetate (1.5 mmol) and SnCl4 -nano-SiO2 (20 mg).
negative pressure on the liquid. If this negative pressure is strong enough, cavities or micro bubbles are formed. Cavitation is considered as a nucleated process, which will be formed at weak points in the liquid, such as gas-filled gaps in suspended particulate mat-
ter or micro bubbles from earlier cavitation events. Therefore, the presence of dispersed nano catalyst in solution during sonication provides nucleation sites for cavity formation over its surface. As micro bubbles are formed, they grow and implode. This process hit the surface with remarkable force and increase mass transfer of organic molecule between liquid and nano catalyst surface. This effect may improve the efficiency of the sonication method [43,46– 48]. Moreover this method, particularly when considering the basic green chemistry concepts, is more environmental friendly. As can be seen from the results in Table 3, aromatic aldehydes with various substituents carrying either electron-donating or electron-withdrawing groups reacted successfully with 1,3dicarbonyl compounds to afford the corresponding products in excellent yields. However, using dimedone instead of ethyl acetoacetate affected the yield and reaction time due to acidity of the methylene protons.
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5
Fig. 5. TEM images of (a) nano-SiO2 and (b) SnCl4 -nano-SiO2 .
O
O
+
ArCHO +
Ar
SnCl4-nano-SiO2 EtOH , U. S.
NH4OAc
O
O
N H
Scheme 1. One-pot synthesis of 1,4-dihydropyridines catalyzed by SnCl4 -nano-SiO2 under ultrasound irradiation.
O O
O
O
H
+
EtO
O
O
SnCl4-nano-SiO2
+
Ph
O
EtO
NH4OAc / EtOH
N H
Scheme 2. Standard model reaction.
OH H O H
H
NH3 ,
)))))
NH2
NH2
O
Ar
O Ar
O
O
O
O
Ar
O
O
)))))
O
Ar
O
O
Ar O
+
)))))
O
+
NH2
NH2 O
HO )))))
H2 O
: SnCl4-nano-SiO2 ))))) : Ultrasonic irradiaton
O
Ar
O
N H Scheme 3. Proposed mechanism for the synthesis of 1,4-dihydropyridines.
Please cite this article as: A. Bamoniri et al., Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst, Journal of the Taiwan Institute of Chemical Engineers (2016), http://dx.doi.org/10.1016/j.jtice.2016.02.018
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Table 2 Optimization of the model reaction using various catalysts under ultrasound irradiation. Entry
Catalyst (g)
Time (min)
Yield (%)a
1 2 3 4 5 6 7 8
None SnCl4 , 0.130 SnCl4 •SiO2 , 0.005 SnCl4 -nano-SiO2 , 0.005 SnCl4 -nano-SiO2 , 0.010 SnCl4 -nano-SiO2 , 0.015 SnCl4 -nano-SiO2 , 0.020 SnCl4 -nano-SiO2 , 0.030
10 10 8 8 5 5 5 5
Trace 65 63 84 89 91 96 96
Table 4 Comparison of some of the results obtained by the present method (ɪ) Fe3 O4 @SiO2 @PPh3 @[CrO3 Br] [54], (ɪɪ) nano-γ -Fe2 O3 [49], (ɪɪɪ) Zr(HPO4 )2 •H2 O [20]. Entry
Catalyst
Time (min)/yield (%) Products
1
ɪ
2
ɪɪ
3
ɪɪɪ
60/93 Table 3, Entry12 15/92 Table 3, Entry 3 120/96 Table 3, Entry 5
45/91 Table 3, Entry10 32/94 Table 3, Entry 4 – –
a Isolated yields: benzaldehyde (1 mmol), ethyl acetoacetate (1 mmol), dimedone (1 mmol) and ammonium acetate (1.5 mmol) in ethanol (5 ml).
The proposed mechanism for the formation of 1,4dihydropyridines in the presence of SnCl4 -nano-SiO2 , which can act as Lewis acid catalyst (empty π orbital of Sn in SnCl4 nano-SiO2 ) is depicted in Scheme 3. As can be seen, the acid–base interaction between SnCl4 -nanoSiO2 and lone pair electrons of oxygen in carbonyl bond causes the formation of corresponding Knoevenagel as well as enamine product. In the following, Michael addition is occurred between these intermediates for the formation of an open chain intermediate under ultrasonic irradiation [49]. The dipolar transition state (TS), that is undergo cyclohydration to furnish the desired products are accelerated better mass transport under ultrasonic irradiation by physical effects. Moreover, reaction in heterogeneous systems (solid–liquid) that proceed via ionic intermediate is influenced predominantly through the mechanical effects of cavitation. Table 4, compares our results with results reported by other groups in the synthesis of 1,4-dihydropyridine derivatives . It is important to note that, SnCl4 -nano-SiO2 acts as an effective catalyst with respect to reaction times and yields. In addition, Zr(HPO4 )2 •H2 O showed decreased in activity after two times while the recovered SnCl4 -nano-SiO2 was reused for four times without considerable loss of its activity. Consequently, it is essential for the solid acid to maintain strong acidity even after recycling and the most important benefit for
Fig. 6. Reusability study of SnCl4 -nano-SiO2 .
commercial applications. Thus, after the completion of the reaction, the reaction mixture was filter under hot condition to separate the catalyst. The recovered catalyst was washed with chloroform and was dried at room temperature without further purification to use for the next run of the current reaction under identical conditions. It was found that the catalyst could be reused for four times without any appreciable loss of its activity (Fig. 6). The XRD of the recovered nanocatalyst was shown in Fig. 7 and so there is no considerable change in its phase. Therefore, the
Table 3 Synthesis of 1,4-dihydropyridine derivatives under reflux conditions and sonication (methods A and B).
O ArCHO +
Entry
1 2 3 4 5 6 7 8 9 10 11 12 a b c
R
C6 H 5 4-MeOC6 H4 4-ClC6 H4 4-NO2 C6 H4 C6 H5 4-MeOC6 H4 4-ClC6 H4 4-NO2 C6 H4 C6 H5 4-MeOC6 H4 4-ClC6 H4 4-NO2 C6 H4
O
Method A
+
NH4OAc
O
Ar
O
SnCl4-nano-SiO2 / EtOH , reflux Method B SnCl4-nano-SiO2 / EtOH , U. S.
1,3-Dicarbonyls
Ethyl acetoacetate Ethyl acetoacetate Ethyl acetoacetate Ethyl acetoacetate Dimedone Dimedone Dimedone Dimedone Ethyl acetoacetate Ethyl acetoacetate Ethyl acetoacetate Ethyl acetoacetate
Product
Ethyl acetoacetate Ethyl acetoacetate Ethyl acetoacetate Ethyl acetoacetate Dimedone Dimedone Dimedone Dimedone Dimedone Dimedone Dimedone Dimedone
4a 4b 4c 4d 4e 4f 4g 4h 4i 4j 4k 4l
N H
.
Time (min)/yield (%)a
M. P. (°C)
Method A
Method B U.S.c
Found
Reported [Ref.]
b 25/92 20/89 25/94 20/90 25/90 15/94 15/92 18/95 15/95 15/89 20/96 20/95
7/96 6/93 5/95 5/97 4/95 4/94 4/98 3/98 5/96 6/94 5/95 4/98
157–160 160–162 145–147 130–132 189–191 269–271 297–299 285–287 225–227 258–260 245–246 240–242
158–160 [50] 161–163 [50] 147–148 [50] 129–131 [50] 190–192 [51] 270–272 [51] 299–230 [52] 286–288 [52] 228–229 [53] 260–262 [53] 245–246 [53] 241–242 [53]
Isolated yields: aryl aldehyde (1 mmol), 1,3-dicarbonyl compounds (2 mmol), ammonium acetate (1.5 mmol) in ethanol (5 ml). SnCl4 -nano-SiO2 (30 mg). SnCl4 -nano-SiO2 (20 mg).
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7
Fig. 7. XRD patterns of recovered SnCl4 -nano-SiO2 after four recovery.
nanocatalyst is stable during synthesis of 1,4-dihydropyridine under ultrasound irradiation. 4. Conclusions In summary, we have developed a convenient, efficient method for the synthesis of 1,4-dihydropyridines via SnCl4 -nano-SiO2 as a highly efficient catalyst under ultrasound irradiation. This ultrasonically approach offers several advantages such as reducing reaction times, high yields, mild reaction conditions and operational simplicity. In addition, low cost, availability, recyclability and low toxicity of the catalyst make this methodology a valid contribution to the existing processes in the field of one-pot multicomponent Hantzsch reaction. Furthermore, the present procedure is readily amenable to parallel synthesis and generation of combinatorial dihydropyridines libraries. Acknowledgement The authors are grateful to University of Kashan for supporting this work by Grant No. (159189/32). Supplementary materials Supplementary material associated with this article can be found, in the online version, at doi:10.1016/j.jtice.2016.02.018. References [1] Triggle DJ. Calcium channel antagonists: clinical uses-past, present and future. Biochem Pharmacol 2007;74:1–9. [2] Eisenberg MJ, Brox A, Bestawros AN. Calcium channel blockers: an update. Am J Med 2004;116:35–43. [3] Bossert F, Meyer H, Wehinger E. 4-Aryldihydropyridines, a new class of highly active calcium antagonists. Angew Chem Int Ed in Engl 1981;20:762–9. [4] Loev B, Goodman MM, Snader KM, Tedeschi R, Macko E. Hantzsch-type dihydropyridine hypotensive agents. J Med Chem 1974;17:956–65. [5] Boer R, Gekeler V. Chemosensitizers in tumor therapy: new compounds promise better efficacy. Drug Future 1995;20:499–510. [6] Bahekar S, Shinde D. Synthesis and anti-inflammatory activity of 1,4dihydropyridines. Acta Pharmaceut 2002;52:281–7. [7] Wächter GA, Davis MC, Martin AR, Franzblau SG. Antimycobacterial activity of substituted isosteres of pyridine-and pyrazinecarboxylic acids. J Med Chem 1998;41:2436–8. [8] Gullapalli S, Ramarao P. L-type Ca 2+ channel modulation by dihydropyridines potentiates κ -opioid receptor agonist induced acute analgesia and inhibits development of tolerance in rats. Neuropharmacology 2002;42:467–75. [9] Sunkel CE, Fau de Casa-Juana M, Santos L, Mar Gomez M, Villarroya M, Gonzalez-Morales MA, Priego JG, Ortega MP. 4-Alkyl-1, 4-dihydropyridine derivatives as specific PAF-acether antagonists. J Med Chem 1990;33:3205–10.
[10] Handkinura MO. Effect of Ca +2 antagonist, vasodilators, diltizem, nifedipine, perhexiline and verapamil on platelet aggregation in vitro. Arzneim-Forsch Drug Res 1981;3:1131–4. [11] Klusa V. Cerebrocrast. Neuroprotectant, cognition enhancer. Drug Future 1995;20:135–8. [12] Sabakhi I. Study and Compraison catalysts that use in producing 1, 4dihydropyridine derivatives compounds. Life Sci J 2013;10:594–9. [13] Parthasarathy K, Jeganmohan M, Cheng CH. Rhodium-catalyzed one-pot synthesis of substituted pyridine derivatives from α , β -unsaturated ketoximes and alkynes. Org Lett 2008;10:325–8. [14] Movassaghi M, Hill MD, Ahmad OK. Direct synthesis of pyridine derivatives. J Am Chem Soc 20 07;129:10 096–7. [15] Movassaghi M, Hill MD. Synthesis of substituted pyridine derivatives via the ruthenium-catalyzed cycloisomerization of 3-azadienynes. J Am Chem Soc 2006;128:4592–3. [16] McCormick MM, Duong HA, Zuo G, Louie J. A nickel-catalyzed route to pyridines. J Am Chem Soc 2005;127:5030–1. [17] Colby DA, Bergman RG, Ellman JA. Rhodium-catalyzed C−C bond formation via heteroatom-directed C−H bond activation. Chem Rev 2010;110:624–55. [18] Barluenga J, Fernández-Rodríguez MÁ, García-García P, Aguilar E. Goldcatalyzed intermolecular hetero-dehydro-diels-alder cycloaddition of captodative dienynes with nitriles: A new reaction and regioselective direct access to pyridines. J Am Chem Soc 2008;130:2764–5. [19] Heravi MM, Bakhtiari K, Javadi NM, Bamoharram FF, Saeedi M, Oskooie HA. K7 [PW11CoO40]-catalyzed one-pot synthesis of polyhydroquinoline derivatives via the Hantzsch three component condensation. J Mol Catal A Chem 2007;264:50–2. [20] Abdolmohammadi S. α -ZrP: a highly efficient catalyst for solvent-free synthesis of pyrimido [5 ,4 :5,6] pyrido [2, 3-d] pyrimidinetetraone and 4arylacridinedione derivatives. Lett Org Chem 2014;11:465–9. [21] Ramesh K, Pasha M. Study on one-pot four-component synthesis of 9-aryl-hexahydro-acridine-1, 8-diones using SiO2 —I as a new heterogeneous catalyst and their anticancer activity. Bioorg Med Chem Lett 2014;24:3907–13. [22] Kumar A, Maurya RA. Efficient synthesis of Hantzsch esters and polyhydroquinoline derivatives in aqueous micelles. Synlett 2008:883–5. [23] Hong M, Cai C, Yi WB. Hafnium (IV) bis (perfluorooctanesulfonyl) imide complex catalyzed synthesis of polyhydroquinoline derivatives via unsymmetrical Hantzsch reaction in fluorous medium. J Fluorine Chem 2010;131:111–14. [24] Debache A, Boulcina R, Belfaitah A, Rhouati S, Carboni B. One-pot synthesis of 1, 4-dihydropyridines via a phenylboronic acid catalyzed Hantzsch threecomponent reaction. Synlet 2008:509–12. [25] Vahdat SM, Mardani HR, Golchoubian H, Khavarpour M, Baghery S, Roshankouhi Z. Cu(II) Schiff base as catalyst in the synthesis of 1,8dioxodecahydroacridine. Comb Chem High Throughput Screening 2013;16:2–6. [26] Singh NB, Singh RJ, Singh NP. Organic solid state reactivity. Tetrahedron 1994;50:6441–93. [27] Desiraju GR. Reactivity of organic solids—retrospect and prospect. Solid State Ionics 1997;101:839–42. [28] Bigdeli MA, Rahmati A, Abbasi-Ghadim H, Mahdavinia GH. SnCl4 and SbCl5 promoted aromatization of enamines. Tetrahedron Lett 2007;48:4575–8. [29] Kita Y, Matsuda S, Inoguchi R, Ganesh JK, Fujioka H. SnCl4 -promoted rearrangement of 2,3-epoxy alcohol derivatives: stereochemical control of the reaction. Tetrahedron Lett 2005;46:89–91. [30] Takeya T, Doi H, Ogata T, Okamoto I, Kotani E. Aerobic oxidative dimerization of 1-naphthols to 2,2 -binaphthoquinones mediated by SnCl4 and its application to natural product synthesis. Tetrahedron 2004;60:9049–60.
Please cite this article as: A. Bamoniri et al., Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst, Journal of the Taiwan Institute of Chemical Engineers (2016), http://dx.doi.org/10.1016/j.jtice.2016.02.018
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[31] Dubost C, Leroy B, IE M, Tinant B, Declercq JP, Bryans J. Stereoselective synthesis of functionalised triol units by SnCl4 promoted allylation of α benzyloxyaldehydes: crucial role of the stoichiometry of the Lewis acid. Tetrahedron 2004;60:7693–704. [32] Li YQ, Cheng LH. A rapid and convenient synthesis of acylals from aldehydes and acetic anhydrides catalyzed by SnCl4 /SiO2 . Chin Chem Lett 2001;12:565–8. [33] Mirjalili BBF, Hashemi MM, Sadeghi B, Emtiazi H. SnCl4 /SiO2 : an efficient heterogeneous alternative for one-pot synthesis of β -acetamidoketones. J Chin Chem Soc 2009;56:386–91. [34] Niknam K, Zolfigol MA, Saberi D, Molaee H. Preparation of silica supported tin chloride: as a recyclable catalyst for the silylation of hydroxyl groups with HMDS. J Chin Chem Soc 2009;56:1257–64. [35] Mirjalili BF, Bamoniri A, Mirhoseini MA. Nano-SnCl4 •SiO2 –a versatile and efficient catalyst for synthesis of 14-aryl-or 14-alkyl-14H-dibenzo [a, j] xanthenes. Chem Heterocycl Compd 2012;48:856–60. [36] Mirjalili BF, Bamoniri A, Mirhoseini MA. Nano-SnCl4 -SiO2 : an efficient catalyst for one-pot synthesis of 2, 4, 5-tri substituted imidazoles under solvent-free conditions. Scientia Iranica 2013;20:587–91. [37] Cravotto G, Cintas P. Power ultrasound in organic synthesis: moving cavitational chemistry from academia to innovative and large-scale applications. Chem Soc Rev 2006;35:180–96. [38] Safari J, Banitaba SH, Dehghan-Khalili S. Ultrasound-promoted an efficient method for one-pot synthesis of 2-amino-4, 6-diphenylnicotinonitriles in water: a rapid procedure without catalyst. Ultrason Sonochem 2012;19:1061–9. [39] Banitaba SH, Safari J, Deghan-Khalili S. Ultrasound promoted one-pot synthesis of 2-amino-4, 8-dihydropyrano [3, 2-b] pyran-3-carbonitrile scaffolds in aqueous media: a complementary green chemistrytool to organic synthesis. Ultrason Sonochem 2013;20:401–7. [40] Moshtael-Arani N, Safari J. A rapid and efficient ultrasound-assisted synthesis of 5, 5-diphenylhydantoins and 5, 5-diphenyl-2-thiohydantoins. Ultrason Sonochem 2011;18:640–3. [41] Khaligh NG, Shirini F. Introduction of poly (4-vinylpyridinium) perchlorate as a new, efficient, and versatile solid acid catalyst for one-pot synthesis of substituted coumarins under ultrasonic irradiation. Ultrason Sonochem 2013;20:26– 31. [42] Khaligh NG. Ultrasound assisted the chemoselective 1, 1-diacetate protection and deprotection of aldehydes catalyzed by poly (4-vinylpyridinium) hydrogen sulfate salt as a eco-benign, efficient and reusable solid acid catalyst. Ultrason Sonochem 2013;20:19–25.
[43] Nagargoje D, Mandhane P, Shingote S, Badadhe P, Gill C. Ultrasound assisted one pot synthesis of imidazole derivatives using diethyl bromophosphate as an oxidant. Ultrason Sonochem 2012;19:94–6. [44] Burger K. Capillary mössbauer spectroscopy (CMS)—a new method for the study of liquids fixed in a suitable carrier. Spectrochim Acta A Mol Spectro 1987;43:1105–10. [45] Ji M, Li X, Wang J, Zhu J, Zhou L. Grafting SnCl4 catalyst as a novel solid acid for the synthesis of 3-methylbut-3-en-1-ol. Catal Today 2011;173:28–31. [46] Wang X, Wei Y, Wang J, Guo W, Wang C. The kinetics and mechanism of ultrasonic degradation of p-nitrophenol in aqueous solution with CCl4 enhancement. Ultrason Sonochem 2012;19:32–7. [47] Gunasekaran P, Perumal S, Yogeeswari P, Sriram D. A facile four-component sequential protocol in the expedient synthesis of novel 2-aryl-5-methyl-2, 3dihydro-1H-3-pyrazolones in water and their antitubercular evaluation. Eur J Med Chem 2011;46:4530–6. [48] Cella R, Stefani HA. Ultrasound in heterocycles chemistry. Tetrahedron 2009;65:2619–41. [49] Kolvari E, Zolfigol M, Koukabi N, Shirmardi-Shaghasemi B. A simple and efficient one-pot synthesis of Hantzsch 1, 4-dihydropyridines using silica sulphuric acid as a heterogeneous and reusable catalyst under solvent-free conditions. Chem Pap 2011;65:898–902. [50] Vanden Eynde JJ, Delfosse F, Mayence A, Van Haverbeke Y. Old reagents, new results: Aromatization of Hantzsch 1, 4-dihydropyridines with manganese dioxide and 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone. Tetrahedron 1995;51:6511–16. [51] Nazario Martin MQ, Seoane C, Soto JL, Mora A, Suarez M, Ochoa E, Morales A, Del Bosque JR. Synthesis and conformational study of acridine derivatives related to 1,4-dihydropyridines. J Heterocyclic Chem 1995;32:235–8. [52] Balalaie S, Chadegani F, Darviche F, Bijanzadeh HR. One-pot synthesis of 1, 8-dioxo-decahydroacridine derivatives in aqueous media. Chin J Chem 2009;27:1953–6. [53] Bandgar B, More P, Kamble V, Totre J. Synthesis of polyhydroquinoline derivatives under aqueous media. Arkivoc 2008:1–8. [54] Maleki A, Rahimi R, Maleki S, Hamidi N. Synthesis and characterization of magnetic bromochromate hybrid nanomaterials with triphenylphosphine surface-modified iron oxide nanoparticles and their catalytic application in multicomponent reactions. RSC Adv 2014;4:29765–71.
Please cite this article as: A. Bamoniri et al., Sonochemically synthesis of 1,4-dihydropyridine derivatives using nano-silica supported tin tetrachloride as a reusable solid acid catalyst, Journal of the Taiwan Institute of Chemical Engineers (2016), http://dx.doi.org/10.1016/j.jtice.2016.02.018