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Catalytic reactions of oxidized n-C10 derivatives over an iron oxide
Applied Catalysis A: General 185 (1999) 153–156
Catalytic reactions of oxidized n-C10 derivatives over an iron oxide J. Wrzyszcz a,∗ , H. Grabowska a , R. Klimkiewicz a , L. Syper b a
Department of Catalysis, W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wroclaw 2, P.O. Box 1410, Poland b Institute of Organic Chemistry, Biochemistry and Biotechnology, Technical University of Wroclaw, Wroclaw, Poland Received 19 February 1999; received in revised form 27 April 1999; accepted 28 April 1999
Abstract The susceptibility to ketonization of oxidized derivatives of n-decane (n-decanol, n-decanal, their equimolar mixtures, n-decyl n-decylate, and 3-hydroxy-2-octyl-dodecanal) in the gas phase at atmospheric pressure over Fe3 O4 catalyst was studied. Using those reactants, 10-nonyldecanone was the main product. Condensing n-decanal, n-decyl n-decylate, and 3-hydroxy-2-octyl-dodecanal, ketone is obtained with higher yields than from n-decanol. ©1999 Elsevier Science B.V. All rights reserved. Keywords: n-Decanol; n-Decanal; n-Decyl n-decylate; 3-Hydroxy-2-octyl-dodecanal; 10-Nonyldecanone; Ketonization; Iron catalyst
1. Introduction The formation of a carbon–carbon bond is an important issue of organic synthesis, since more complex products are obtained from simple molecules as its result. We have recently described a catalytic condensation of two molecules of primary normal alcohols to symmetric ketones [1]. Ketonization reactions of primary normal alcohols occurring in the presence of catalysts in the gas phase run according to the summary equation 2RCH2 OH → RCOR + CO + 3H2 . The reaction is of consecutive character; so at moderate temperatures the presence of an aldehyde and ester is detected, while at higher temperatures a ketone is the main product. Data concerning the yield of ketones obtained from higher alcohols are inconsistent, evidence of which are good results of Komarewsky et al. [2,3] obtained in the presence of ∗
Corresponding author. E-mail: [email protected]
a chromium catalyst, while Iwasa and Takezawa [4] have, using copper catalysts, found that “dehydrogenation of higher alcohols is poorly selective. The aldehydes and ketones formed partly undergo aldol condensation and/or transformation to esters”. There has been a series of suggestions published in the literature concerning the mechanism of those reactions, yet they are contradictory at many points [2–8] and not always in accordance with the principles of modern organic chemistry.
2. Experiments Studying ketonization reactions of normal alcohols C4 –C12 in the presence of an iron catalyst, it has been established that this contact belongs to a group of catalysts that exhibits high activity and selectivity. A mechanism of the ketonization reaction occurring in its presence has also been proposed [1] in the sequence
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alcohol → aldehyde → hemiacetal → ester → -ketoester → ketone.
(1)
The catalyst and reaction system used were as described before [9]. Shortly, the catalyst containing Fe, Si, Cr and K oxides in the molar ratio of 100 : 2 : 1 : 0.1 was placed in a typical flow reactor. The ketonization reactions were carried out over the iron catalyst (Vcat. = 3.0 cm3 , LHSV = 9.0 cm3 cm−3 h−1 ) in the gas phase at the atmospheric pressure in the temperature range of 583–673 K. Obtained compounds were identified using GC/MS method.
3. Results and discussion It was of interest to study the reactivity — susceptibility to ketonization — of the intermediate compounds occurring in this reaction. For that reason, experiments of ketonization of n-decanol (1), n-decanal (2), their equimolar mixtures, n-decyl n-decylate (3), and 3-hydroxy-2-octyl-dodecanal (4) have been carried out. Using those reactants, we have always obtained 10-nonyldecanone (5) as the main product, which indicates a more general character of the reaction described.
The results of condensation of n-decanol and n-decanal obtained by applying the load of 3.0 h−1 in the temperature range of 583–673 K have been presented in Fig. 1. The principal difference in ketonization of the aldehyde 2 and the alcohol 1 is the fact that the aldehyde condenses to the ketone 5 with a higher yield than in the case of the alcohol, which is consistent with a statement by Komarewsky [2] that aldehydes are intermediate compounds of the ketonization of primary alcohols. The amount of the ester 3 formed is, however, significantly lower than the amount formed during condensation of the alcohol. In Fig. 1, we also present the results of condensation of an equimolar mixture of the alcohol 1 with the aldehyde 2. Such a mixture is equivalent to the
Fig. 1. Results of condensation of n-decanol, n-decanal and their equimolar mixture obtained at the load of 3.0 h−1 . X = conversion of substrates (n-decanol, curve 1; equimolar mixture of n-decanol and n-decanal, curve 2; n-decanal, curve 3) and yields of products (ester from n-decanol, curve 4; ester from equimolar mixture of n-decanol and n-decanal, curve 5; ester from n-decanal, curve 6; ketone from n-decanol, curve 7; ketone from equimolar mixture of n-decanol and n-decanal, curve 8; ketone from n-decanal, curve 9)
hemiacetal CH3 (CH2 )9 OCH(OH)(CH2 )8 CH3 6, since an alcohol mixed with an aldehyde immediately forms a hemiacetal. As a result of the condensation of that mixture, a significantly higher yield of the ester was obtained, which reached 23% at the temperature of 627 K, whereas for the condensation of n-decanol or n-decanal alone the maximum yields obtained were 21.1 and 8.0%, respectively. This fact can make for an argument that the transformation proceeds via hemiacetal in the sequence alcohol → aldehyde → hemiacetal → ester → ketone. It is interesting, though, that in the presence of a copper catalyst, the aldehyde alone does not undergo any condensation at all [10]. The amount of the ketone obtained from a mixture of the alcohol and the aldehyde reaches intermediate values between the amounts obtained from the alcohol or from the aldehyde. In Table 1, the results of transformation of the ester 3 to the ketone 5 have been presented, which proceeds with a yield of over 65%, higher than from the alcohol. It should be remembered here, however,
J. Wrzyszcz et al. / Applied Catalysis A: General 185 (1999) 153–156
155
Table 1 The results of n-decyl n-decylate reactions over an iron catalyst Reaction temperature (K)
583 595 610 618 627 640 653 663 673
Conversion (%)
1.5 2.0 4.2 8.2 21.0 46.1 76.0 94.5 99.8
Yield of reaction products (%) n-decene
n-decane
n-decanal
n-decanol
10-nonyldecanone
others
– – – – 2.0 2.8 4.5 7.2 6.2
– 0.3 0.6 1.6 4.7 7.0 9.7 17.1 14.5
1.0 1.1 1.2 2.2 2.5 5.0 0.1 – –
0.5 0.6 0.8 1.2 3.5 7.5 1.2 – –
– – – traces 4.1 18.7 53.3 62.2 65.6
– – 0.6 0.7 0.7 0.6 1.2 1.0 2.5
Table 2 The results of 3-hydroxy-2-octyl-dodecanal reactions over an iron catalyst Reaction temperature (K)
583 595 610 627 640 653 663 673
Conversion (%)
6.5 7.1 9.0 29.6 82.6 98.5 99.2 99.7
Yield of reaction products (%) n-decene
n-decane
n-decanol
n-decyl n-decylate
10-nonyldecanone
others
– – – – traces traces 0.9 1.1
– – – – traces 0.8 2.1 2.5
0.3 0.9 1.3 1.2 1.2 – – –
4.2 4.6 4.7 5.0 8.8 7.7 5.8 3.8
– – – 15.1 58.4 74.3 69.0 68.0
– – –
that during ketonization of an ester, the load of the catalyst, when translated into moles, is half as big as is in the case of an alcohol, and that the stoichiometry of that reaction is different, since, besides the ketone and carbon monoxide, only one molecule of hydrogen is formed. As a result of the transformation of the ester at lower temperatures n-decanol is formed, which then undergoes secondary condensation. It indicates that the course of transformation via -ketoester postulated in the paper [1] may be well-founded, though other possibilities of the formation of alcohol from an ester have also been suggested in the literature, viz., as a result of Kagan reaction [11] or via hydrogenolysis [12]. In the products of the transformation of n-butanol carried out using the same iron catalyst, derivatives of an aldol were found, e.g. 2-ethylhexen-2-al [9]. So, it was purposeful to examine the course of reaction of the 3-hydroxy-2-octyl-dodecanal (4). Table 2 presents the conversion and yields of products in function of
3.8 8.2 8.6 11.9 11.3
temperature. In the case of the compound 4, similar yields of ester are obtained as in the case of aldehyde, but it undergoes the reaction to ketone significantly faster. In this case, the maximum yield of ketone is obtained at a temperature over 20◦ lower than for an aldehyde. This result indicates a possibility of transformation of alcohol in accordance to the sequence alcohol → aldehyde → aldol → ketone cannot be excluded. Higher conversion of 3-hydroxy-2-octyl-dodecanal in dependence on temperature may be explained, similarly as in the case of ester, by lower amount of moles of raw material introduced to catalyst bed in the unit of time and different stoichiometry of the reaction. In the case of reaction of the compound 4, it should be taken into account that under the condition of the process it could break into two molecules of the aldehyde 2; retro aldol reaction is quite a widespread phenomenon.
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4. Conclusions
Acknowledgements
Results of experiments, by example of n-decanol, n-decanal, n-decyl n-decylate and 3-hydroxy-2-octyldodecanal, have shown that both higher alcohols and their oxygen derivatives present in the products of ketonization of alcohols undergo transformations to 10-nonyldecanone with similar yields. It should be noted, however, that condensing oxygen derivatives of n-decanol in the presence of an iron catalyst, ketone is obtained with higher yields than from alcohol. The course of ketonization of a mixture of n-decanol with n-decanal, as well as the presence of alcohol in the products of ketonization of an ester, are in agreement with the mechanism of transformation reaction we postulated earlier Eq. (1):
The research was performed with the financial support from the Polish State Committee for Scientific Research under Grant no. 3T09B06011.
CH3 (CH2 )7 CH2 CH2 OH → CH3 (CH2 )7 CH2 CHO → CH3 (CH2 )7 CH2 CH(OH)OCH2 (CH2 )8 CH3 → CH3 (CH2 )7 CH2 COOCH2 (CH2 )8 CH3 → CH3 (CH2 )7 CH2 COCH(C8 H17 ) COOCH2 (CH2 )8 CH3 → CH3 (CH2 )8 CO(CH2 )8 CH3 . Yet, this mechanism cannot be regarded as definitely established.
References [1] J. Wrzyszcz, H. Grabowska, R. Klimkiewicz, L. Syper, Catal. Lett. 54 (1998) 55. [2] V.I. Komarewsky, J.R. Coley, J. Am. Chem. Soc. 63 (1941) 700. [3] V.I. Komarewsky, J.R. Coley, J. Am. Chem. Soc. 63 (1941) 3269. [4] N. Iwasa, N. Takezawa, Bull. Chem. Soc. Jpn. 64 (1991) 2619. [5] B.N. Dolgow, Die Katalyse in der Organischen Chemie, VEB Deutscher Verlag der Wissenschaften, Berlin, 1963, pp. 268–285. [6] K. Kawamoto, Y. Nishimura, Bull. Chem. Soc. Jpn. 44 (1971) 819. [7] G.A. Loginov, M.A. Markov, Kh.M. Minachev, Neftekhimiya 10 (1970) 393. [8] J.B. Claridge, M.L.H. Green, S.C. Tsang, A.P.E. York, J. Chem. Soc. Faraday Trans. 89 (1993) 1089. [9] H. Grabowska, R. Klimkiewicz, Pol. J. Chem. 72 (1998) 141. [10] K. Takeshita, S. Nakamura, K. Kawamoto, Bull. Chem. Soc. Jpn. 51 (1978) 2622. [11] M.J. Kagan, I.A. Sobolev, T.D. Lubarskii, Chem. Ber. 68 (1935) 1140. [12] T. Turek, D.L. Trimm, Catal. Rev. Sci. Eng. 36 (1994) 645.
Catalytic reactions of oxidized n-C10 derivatives over an iron oxide J. Wrzyszcz a,∗ , H. Grabowska a , R. Klimkiewicz a , L. Syper b a
Department of Catalysis, W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wroclaw 2, P.O. Box 1410, Poland b Institute of Organic Chemistry, Biochemistry and Biotechnology, Technical University of Wroclaw, Wroclaw, Poland Received 19 February 1999; received in revised form 27 April 1999; accepted 28 April 1999
Abstract The susceptibility to ketonization of oxidized derivatives of n-decane (n-decanol, n-decanal, their equimolar mixtures, n-decyl n-decylate, and 3-hydroxy-2-octyl-dodecanal) in the gas phase at atmospheric pressure over Fe3 O4 catalyst was studied. Using those reactants, 10-nonyldecanone was the main product. Condensing n-decanal, n-decyl n-decylate, and 3-hydroxy-2-octyl-dodecanal, ketone is obtained with higher yields than from n-decanol. ©1999 Elsevier Science B.V. All rights reserved. Keywords: n-Decanol; n-Decanal; n-Decyl n-decylate; 3-Hydroxy-2-octyl-dodecanal; 10-Nonyldecanone; Ketonization; Iron catalyst
1. Introduction The formation of a carbon–carbon bond is an important issue of organic synthesis, since more complex products are obtained from simple molecules as its result. We have recently described a catalytic condensation of two molecules of primary normal alcohols to symmetric ketones [1]. Ketonization reactions of primary normal alcohols occurring in the presence of catalysts in the gas phase run according to the summary equation 2RCH2 OH → RCOR + CO + 3H2 . The reaction is of consecutive character; so at moderate temperatures the presence of an aldehyde and ester is detected, while at higher temperatures a ketone is the main product. Data concerning the yield of ketones obtained from higher alcohols are inconsistent, evidence of which are good results of Komarewsky et al. [2,3] obtained in the presence of ∗
Corresponding author. E-mail: [email protected]
a chromium catalyst, while Iwasa and Takezawa [4] have, using copper catalysts, found that “dehydrogenation of higher alcohols is poorly selective. The aldehydes and ketones formed partly undergo aldol condensation and/or transformation to esters”. There has been a series of suggestions published in the literature concerning the mechanism of those reactions, yet they are contradictory at many points [2–8] and not always in accordance with the principles of modern organic chemistry.
2. Experiments Studying ketonization reactions of normal alcohols C4 –C12 in the presence of an iron catalyst, it has been established that this contact belongs to a group of catalysts that exhibits high activity and selectivity. A mechanism of the ketonization reaction occurring in its presence has also been proposed [1] in the sequence
0926-860X/99/$ – see front matter ©1999 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 6 - 8 6 0 X ( 9 9 ) 0 0 1 3 6 - 2
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J. Wrzyszcz et al. / Applied Catalysis A: General 185 (1999) 153–156
alcohol → aldehyde → hemiacetal → ester → -ketoester → ketone.
(1)
The catalyst and reaction system used were as described before [9]. Shortly, the catalyst containing Fe, Si, Cr and K oxides in the molar ratio of 100 : 2 : 1 : 0.1 was placed in a typical flow reactor. The ketonization reactions were carried out over the iron catalyst (Vcat. = 3.0 cm3 , LHSV = 9.0 cm3 cm−3 h−1 ) in the gas phase at the atmospheric pressure in the temperature range of 583–673 K. Obtained compounds were identified using GC/MS method.
3. Results and discussion It was of interest to study the reactivity — susceptibility to ketonization — of the intermediate compounds occurring in this reaction. For that reason, experiments of ketonization of n-decanol (1), n-decanal (2), their equimolar mixtures, n-decyl n-decylate (3), and 3-hydroxy-2-octyl-dodecanal (4) have been carried out. Using those reactants, we have always obtained 10-nonyldecanone (5) as the main product, which indicates a more general character of the reaction described.
The results of condensation of n-decanol and n-decanal obtained by applying the load of 3.0 h−1 in the temperature range of 583–673 K have been presented in Fig. 1. The principal difference in ketonization of the aldehyde 2 and the alcohol 1 is the fact that the aldehyde condenses to the ketone 5 with a higher yield than in the case of the alcohol, which is consistent with a statement by Komarewsky [2] that aldehydes are intermediate compounds of the ketonization of primary alcohols. The amount of the ester 3 formed is, however, significantly lower than the amount formed during condensation of the alcohol. In Fig. 1, we also present the results of condensation of an equimolar mixture of the alcohol 1 with the aldehyde 2. Such a mixture is equivalent to the
Fig. 1. Results of condensation of n-decanol, n-decanal and their equimolar mixture obtained at the load of 3.0 h−1 . X = conversion of substrates (n-decanol, curve 1; equimolar mixture of n-decanol and n-decanal, curve 2; n-decanal, curve 3) and yields of products (ester from n-decanol, curve 4; ester from equimolar mixture of n-decanol and n-decanal, curve 5; ester from n-decanal, curve 6; ketone from n-decanol, curve 7; ketone from equimolar mixture of n-decanol and n-decanal, curve 8; ketone from n-decanal, curve 9)
hemiacetal CH3 (CH2 )9 OCH(OH)(CH2 )8 CH3 6, since an alcohol mixed with an aldehyde immediately forms a hemiacetal. As a result of the condensation of that mixture, a significantly higher yield of the ester was obtained, which reached 23% at the temperature of 627 K, whereas for the condensation of n-decanol or n-decanal alone the maximum yields obtained were 21.1 and 8.0%, respectively. This fact can make for an argument that the transformation proceeds via hemiacetal in the sequence alcohol → aldehyde → hemiacetal → ester → ketone. It is interesting, though, that in the presence of a copper catalyst, the aldehyde alone does not undergo any condensation at all [10]. The amount of the ketone obtained from a mixture of the alcohol and the aldehyde reaches intermediate values between the amounts obtained from the alcohol or from the aldehyde. In Table 1, the results of transformation of the ester 3 to the ketone 5 have been presented, which proceeds with a yield of over 65%, higher than from the alcohol. It should be remembered here, however,
J. Wrzyszcz et al. / Applied Catalysis A: General 185 (1999) 153–156
155
Table 1 The results of n-decyl n-decylate reactions over an iron catalyst Reaction temperature (K)
583 595 610 618 627 640 653 663 673
Conversion (%)
1.5 2.0 4.2 8.2 21.0 46.1 76.0 94.5 99.8
Yield of reaction products (%) n-decene
n-decane
n-decanal
n-decanol
10-nonyldecanone
others
– – – – 2.0 2.8 4.5 7.2 6.2
– 0.3 0.6 1.6 4.7 7.0 9.7 17.1 14.5
1.0 1.1 1.2 2.2 2.5 5.0 0.1 – –
0.5 0.6 0.8 1.2 3.5 7.5 1.2 – –
– – – traces 4.1 18.7 53.3 62.2 65.6
– – 0.6 0.7 0.7 0.6 1.2 1.0 2.5
Table 2 The results of 3-hydroxy-2-octyl-dodecanal reactions over an iron catalyst Reaction temperature (K)
583 595 610 627 640 653 663 673
Conversion (%)
6.5 7.1 9.0 29.6 82.6 98.5 99.2 99.7
Yield of reaction products (%) n-decene
n-decane
n-decanol
n-decyl n-decylate
10-nonyldecanone
others
– – – – traces traces 0.9 1.1
– – – – traces 0.8 2.1 2.5
0.3 0.9 1.3 1.2 1.2 – – –
4.2 4.6 4.7 5.0 8.8 7.7 5.8 3.8
– – – 15.1 58.4 74.3 69.0 68.0
– – –
that during ketonization of an ester, the load of the catalyst, when translated into moles, is half as big as is in the case of an alcohol, and that the stoichiometry of that reaction is different, since, besides the ketone and carbon monoxide, only one molecule of hydrogen is formed. As a result of the transformation of the ester at lower temperatures n-decanol is formed, which then undergoes secondary condensation. It indicates that the course of transformation via -ketoester postulated in the paper [1] may be well-founded, though other possibilities of the formation of alcohol from an ester have also been suggested in the literature, viz., as a result of Kagan reaction [11] or via hydrogenolysis [12]. In the products of the transformation of n-butanol carried out using the same iron catalyst, derivatives of an aldol were found, e.g. 2-ethylhexen-2-al [9]. So, it was purposeful to examine the course of reaction of the 3-hydroxy-2-octyl-dodecanal (4). Table 2 presents the conversion and yields of products in function of
3.8 8.2 8.6 11.9 11.3
temperature. In the case of the compound 4, similar yields of ester are obtained as in the case of aldehyde, but it undergoes the reaction to ketone significantly faster. In this case, the maximum yield of ketone is obtained at a temperature over 20◦ lower than for an aldehyde. This result indicates a possibility of transformation of alcohol in accordance to the sequence alcohol → aldehyde → aldol → ketone cannot be excluded. Higher conversion of 3-hydroxy-2-octyl-dodecanal in dependence on temperature may be explained, similarly as in the case of ester, by lower amount of moles of raw material introduced to catalyst bed in the unit of time and different stoichiometry of the reaction. In the case of reaction of the compound 4, it should be taken into account that under the condition of the process it could break into two molecules of the aldehyde 2; retro aldol reaction is quite a widespread phenomenon.
156
J. Wrzyszcz et al. / Applied Catalysis A: General 185 (1999) 153–156
4. Conclusions
Acknowledgements
Results of experiments, by example of n-decanol, n-decanal, n-decyl n-decylate and 3-hydroxy-2-octyldodecanal, have shown that both higher alcohols and their oxygen derivatives present in the products of ketonization of alcohols undergo transformations to 10-nonyldecanone with similar yields. It should be noted, however, that condensing oxygen derivatives of n-decanol in the presence of an iron catalyst, ketone is obtained with higher yields than from alcohol. The course of ketonization of a mixture of n-decanol with n-decanal, as well as the presence of alcohol in the products of ketonization of an ester, are in agreement with the mechanism of transformation reaction we postulated earlier Eq. (1):
The research was performed with the financial support from the Polish State Committee for Scientific Research under Grant no. 3T09B06011.
CH3 (CH2 )7 CH2 CH2 OH → CH3 (CH2 )7 CH2 CHO → CH3 (CH2 )7 CH2 CH(OH)OCH2 (CH2 )8 CH3 → CH3 (CH2 )7 CH2 COOCH2 (CH2 )8 CH3 → CH3 (CH2 )7 CH2 COCH(C8 H17 ) COOCH2 (CH2 )8 CH3 → CH3 (CH2 )8 CO(CH2 )8 CH3 . Yet, this mechanism cannot be regarded as definitely established.
References [1] J. Wrzyszcz, H. Grabowska, R. Klimkiewicz, L. Syper, Catal. Lett. 54 (1998) 55. [2] V.I. Komarewsky, J.R. Coley, J. Am. Chem. Soc. 63 (1941) 700. [3] V.I. Komarewsky, J.R. Coley, J. Am. Chem. Soc. 63 (1941) 3269. [4] N. Iwasa, N. Takezawa, Bull. Chem. Soc. Jpn. 64 (1991) 2619. [5] B.N. Dolgow, Die Katalyse in der Organischen Chemie, VEB Deutscher Verlag der Wissenschaften, Berlin, 1963, pp. 268–285. [6] K. Kawamoto, Y. Nishimura, Bull. Chem. Soc. Jpn. 44 (1971) 819. [7] G.A. Loginov, M.A. Markov, Kh.M. Minachev, Neftekhimiya 10 (1970) 393. [8] J.B. Claridge, M.L.H. Green, S.C. Tsang, A.P.E. York, J. Chem. Soc. Faraday Trans. 89 (1993) 1089. [9] H. Grabowska, R. Klimkiewicz, Pol. J. Chem. 72 (1998) 141. [10] K. Takeshita, S. Nakamura, K. Kawamoto, Bull. Chem. Soc. Jpn. 51 (1978) 2622. [11] M.J. Kagan, I.A. Sobolev, T.D. Lubarskii, Chem. Ber. 68 (1935) 1140. [12] T. Turek, D.L. Trimm, Catal. Rev. Sci. Eng. 36 (1994) 645.