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Sodium dithionite initiated addition–sulfination reaction of perfluoroalkyl bromides and olefins
Journal of Fluorine Chemistry 93 (1999) 49±51
Sodium dithionite initiated addition±sul®nation reaction of per¯uoroalkyl bromides and ole®ns Jin-Tao Liu*, Guo-Dong Sui, Gang Chen, Wei-Yuan Huang
Laboratory of Organo¯uorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, PR China Received 6 July 1998; accepted 10 September 1998
Abstract In the presence of sodium dithionite, per¯uoroalkyl bromides reacted with ole®ns readily in aqueous iso-propanol solution under mild conditions, giving the corresponding addition±sul®nation products, RFCH2CH(R)SO2Na, in good yields. A radical mechanism was proposed for this reaction. # 1999 Elsevier Science S.A. All rights reserved. Keywords: Per¯uoroalkyl bromides; Sodium dithionite; Addition±sul®nation
1. Introduction Both per¯uoroalkyl iodides and bromides reacted with sodium dithionite to give the corresponding per¯uoroalkanesul®nates through a radical process [1,2], and 1:1 adducts were obtained when per¯uoroalkyl iodides reacted with ole®ns initiated by sodium dithionite in aqueous acetonitrile solution [3]. Under similar conditions, the reaction of per¯uoroalkyl bromides with ole®ns was more dif®cult and complicated. Further studies showed that an addition±sul®nation reaction occurred when per¯uoroalkyl bromides were allowed to react with ole®ns in aqueous iso-propanol solution. Herein we report the results of this reaction.
played an important role in this reaction. In aqueous isopropanol solution, no byproduct or only trace amount of RFCH2CHBrR was detected, while byproducts such as RFSO2Na and RFCH2CHBrR were formed when CH3CN, C2H5OH, DMF and THF were used as co-solvent in this reaction. The sul®natodebromination reaction of per¯uoroalkyl bromides has been proved to be a radical process in which a per¯uoroalkyl radical was formed as a key intermediate [2]. The fact that a cyclic product was obtained in the reaction of per¯uoroalkyl bromide with diallyl ether indicated that a radical intermediate is involved in the above addition±sul®nation reaction. Thus the following mechanism was proposed:
2. Results and Discussion In the presence of sodium dithionite, per¯uoroalkyl bromides (1) readily reacted with ole®ns in aqueous iso-propanol solution at 60±708C, giving the corresponding addition±sul®nation products (3) in good yields (Scheme 1). The sul®nates were isolated and characterized by converting them to their corresponding sulfonyl chloride (4) with chlorine. The results are listed in Table 1. As shown in Table 1, both ethylene and terminal alkenes with longer chain could react with per¯uoroalkyl bromides to give addition±sul®nation products directly. Solvents
*Corresponding author. Fax: +86-2164-166-128.
The reaction of compound 4 with potassium hydroxide gave the corresponding potassium sulfonate 5 (Scheme 2), a new special and useful hybrid anionic surfactant containing ¯uorocarbon and hydrocarbon chains [4].
0022-1139/99/$ ± see front matter # 1999 Elsevier Science S.A. All rights reserved. PII: S0022-1139(98)00281-4
50
J.-T. Liu et al. / Journal of Fluorine Chemistry 93 (1999) 49±51
Scheme 1.
Table 1 The reaction of perfluoroalkyl bromides with olefins:
using TFA as external standard. The values reported were CFCl3 TFA 76:8 ppm, positive for up®eld shifts. Mass spectra were taken on a Finnegan GC±MS 4021 spectrometer.
Na2 S2 O4
RF Br 1 CH2 CHR 2 ! RF CH2 CH RSO2 Na 3 Cl2
! RFCH2 CH RSO2 Cl 4 Entry
RFBr
Olefin
Product
Yield (%)a
1 2 3 4 5 6 7 8
1a 1b 1c 1c 1d 1d 1d 1d
2b 2b 2a 2d 2a 2b 2c 2e
4ab 4bb 4ca 4cd 4da 4db 4dc 4de
67 69 73 57 64 74 72 65
a
Isolated yields of two steps based on RFBr.
In conclusion, the addition±sul®nation reaction of per¯uoroalkyl bromides and ole®ns has been achieved by initiation with sodium dithionite under mild conditions, providing a facile method for the synthesis of a new type of hybrid anionic surfactant. 3. Experimental IR spectra were measured with a Shimadzu IR-440 spectrometer, using liquid ®lms. 1 H NMR spectra were recorded on a Bruker AM 300 (300 MHz) spectrometer, using TMS as internal standard. 19 F NMR spectra were recorded on a Varian EM-360L spectrometer (56.4 MHz)
Scheme 2.
3.1. Typical procedure A mixture of Cl(CF2)6Br (10 mmol), n-C6H12 (20 mmol), Na2S2O4 (15 mmol) and NaHCO3 (15 mmol) in i-PrOH (15 ml) and H2O (15 ml) was stirred at 708C for 6 h. Then Cl2 was bubbled through the mixture at 0±58C for 5 h. The product was extracted with ether, washed with water and dried over anhydrous Na2SO4. After removal of ether, the crude product was puri®ed by column chromatography on silica gel to give 4db in 74% yield as a colorless liquid. 1 H NMR(300 MHz, CDCl3) 3.88 (m, 1H), 3.15±2.42 (m, 2H), 2.30±1.95 (m, 2H), 1.55 (m, 2H), 1.36 (m, 2H), 0.92 (t, 3H) ppm; 19 F NMR(56.4 MHz, CDCl3) 68.2 (s, 2F), 111.0 (m, 2F), 119.1 (m, 2F), 120.0 (m, 4F), 121.8 (m, 2F) ppm; IR (, cmÿ1) 2964, 2870, 1470, 1440, 1380, 1210, 1160; MS(m/z) 518 (M), 419 (M-SO2Cl); Anal. Calcd for C12H12Cl2F12O2S: C 27.76, H 2.33, Cl 13.65, F 43.91, S 6.18; Found: C 27.63, H 2.27, Cl 13.78, F 44.42, S 6.23%. 4ab: 1 H NMR(300 MHz, CDCl3) 3.88 (m, 1H), 3.15± 2.42 (m, 2H), 2.30±1.94 (m, 2H), 1.58 (m, 2H), 1.38 (m, 2H), 0.92 (t, 3H) ppm; 19 F NMR(56.4 MHz, CDCl3) 80.3 (s, 3F), 112.8 (m, 2F), 121.3±123.0 (m, 6F), 125.8 (m, 2F) ppm; IR (, cmÿ1) 2970, 2930, 2862, 1466, 1365, 1242, 1208, 1148; MS(m/z) 503 (M1), 403 (M-SO2Cl); Anal. Calcd for C12H12ClF13O2S: C 28.67, H 2.40, F 49.13, S 6.38; Found: C 28.47, H 2.76, F 49.55, S 6.25%. 4bb: 1 H NMR(300 MHz, CDCl3) 3.90 (m, 1H), 3.15± 2.44 (m, 2H), 2.30±1.95 (m, 2H), 1.55 (m, 2H), 1.40 (m, 2H), 0.95 (t, 3H) ppm; 19 F NMR(56.4 MHz, CDCl3) 81.0 (s, 3F), 112.2 (m, 2F), 121.7±123.0 (m, 10F), 126.2 (m, 2F) ppm; IR (, cmÿ1) 2963, 2937, 2877, 1466, 1372, 1208, 1152; MS(m/z) 603 (M1), 503 (M-SO2Cl); Anal. Calcd for C14H12ClF17O2S: C 27.90, H 2.01, F 53.58, S 5.32; Found: C 28.20, H 2.02, F 53.25, S 5.23%.
J.-T. Liu et al. / Journal of Fluorine Chemistry 93 (1999) 49±51
4cd: 1 H NMR(300 MHz, CDCl3) 3.88 (m, 1H), 3.14±2.42 (m, 2H), 2.30±1.95 (m, 2H), 1.56 (m, 2H), 1.30 (m, 10H), 0.90 (t, 3H) ppm; 19 F NMR(56.4 MHz, CDCl3) 67.5 (s, 2F), 111.8 (m, 2F), 119.2 (m, 2F), 122.0 (m, 2F) ppm; IR (, cmÿ1) 2930, 2858, 1465, 1430, 1382, 1190, 1138; MS(m/z) 475 (M1), 375 (M-SO2Cl); Anal. Calcd for C14H20Cl2F8O2S: C 35.38, H 4.24, F 31.98, S 6.74; Found: C 35.50, H 4.60, F 32.35, S 6.52%. 4dc: 1 H NMR(300 MHz, CDCl3) 3.90 (m, 1H), 3.15±2.42 (m, 2H), 2.32±1.95 (m, 2H), 1.56 (m, 2H), 1.32 (m, 6H), 0.90 (t, 3H) ppm; 19 F NMR(56.4 MHz, CDCl3) 68.2 (s, 2F), 113.0 (m, 2F), 120.6 (m, 2F), 121.8 (m, 4F), 123.8 (m, 2F) ppm; IR (, cmÿ1) 2930, 2861, 1458, 1432, 1378, 1212, 1152; MS(m/z) 546 (M), 447 (M-SO2Cl); Anal. Calcd for C14H16Cl2F12O2S: C 30.73, H 2.95, F 41.66, S 5.86; Found: C 30.56, H 2.82, F 41.93, S 5.72%. 4de: 1 H NMR(300 MHz, CDCl3) 4.10±3.58 (m, 6H), 3.10±2.90 (m, 2H), 2.18 (m, 2H) ppm; 19 F NMR(56.4 MHz, CDCl3) 67.6 (s, 2F), 113.2 (m, 2F), 120.0 (m, 2F), 121.2 (m, 4F), 123.3 (m, 2F) ppm; IR (, cmÿ1) 2907, 1375, 1200, 1165; MS(m/z) 532 (M), 433 (M-SO2Cl); Anal. Calcd for C12H10Cl2F12O3S: C 27.03, H 1.89, F 42.76, S 6.01; Found: C 27.22, H 1.77, F 42.72, S 6.06%. 3.2. The reaction of perfluoroalkyl bromides with ethylene To a 100 ml-autoclave were added Cl(CF2)4Br (4 mmol), Na2S2O4 (6 mmol), NaHCO3 (6 mmol), i-PrOH (5 ml) and H2O (5 ml). Then ethylene was added and the mixture was stirred at 708C and 8±12 atm for 24 h. Workup as above gave 4ca in 73% yield. 1 H NMR(300 MHz, CDCl3) 3.94 (m,
51
2H), 2.85 (m, 2H) ppm; 19 F NMR(56.4 MHz, CDCl3) 67.8 (s, 2F), 113.0 (m, 2F), 119.8 (m, 2F), 122.4 (m, 2F) ppm; IR (, cmÿ1) 3008, 2942, 1443, 1371, 1192, 1138; MS(m/z) 362 (M), 263 (M-SO2Cl); Anal. Calcd for C6H4Cl2F8O2S: C 19.85, H 1.11, F 41.86, S 8.83; Found: C 19.69, H 1.06, F 41.46, S 8.61%. 4da: 1 H NMR(300 MHz, CDCl3) 3.95 (m, 2H), 2.85 (m, 2H) ppm; 19 F NMR(56.4 MHz, CDCl3) 67.6 (s, 2F), 113.0 (m, 2F), 119.1 (m, 2F), 121.2 (m, 4F), 123.0 (m, 2F) ppm; IR (, cmÿ1) 3008, 2942, 1443, 1371, 1192, 1138; MS(m/z) 462 (M), 363 (M-SO2Cl); Anal. Calcd for C8H4Cl2F12O2S: C 20.75, H 0.87, F 49.23, S 6.92; Found: C 20.41, H 0.78, F 48.91, S 6.91%. Acknowledgements We are grateful to the Chinese Natural Science Foundation for ®nancial support (grant no. 29 772 041). References [1] W.-Y. Huang, B.-N. Huang, W. Wang, Acta Chimica Sinica (Engl. Ed.) (1985) 253. [2] B.-N. Huang, B.-H. Wang, W. Wang, W.-Y. Huang, Acta Chimica Sinica (Engl. Ed.) (1986) 68. [3] W.-Y. Huang, W. Wang, B.-N. Huang, Acta Chimica Sinica (Engl. Ed.) (1986) 178. [4] M. Abe, K. Tobita, H. Sakai, Y. Kondo, N. Yoshino, Y. Kasahara, H. Matsuzawa, M. Iwahashi, N. Momozawa, K. Nishiyama, Langmuir 13 (1997) 2932.
Sodium dithionite initiated addition±sul®nation reaction of per¯uoroalkyl bromides and ole®ns Jin-Tao Liu*, Guo-Dong Sui, Gang Chen, Wei-Yuan Huang
Laboratory of Organo¯uorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, PR China Received 6 July 1998; accepted 10 September 1998
Abstract In the presence of sodium dithionite, per¯uoroalkyl bromides reacted with ole®ns readily in aqueous iso-propanol solution under mild conditions, giving the corresponding addition±sul®nation products, RFCH2CH(R)SO2Na, in good yields. A radical mechanism was proposed for this reaction. # 1999 Elsevier Science S.A. All rights reserved. Keywords: Per¯uoroalkyl bromides; Sodium dithionite; Addition±sul®nation
1. Introduction Both per¯uoroalkyl iodides and bromides reacted with sodium dithionite to give the corresponding per¯uoroalkanesul®nates through a radical process [1,2], and 1:1 adducts were obtained when per¯uoroalkyl iodides reacted with ole®ns initiated by sodium dithionite in aqueous acetonitrile solution [3]. Under similar conditions, the reaction of per¯uoroalkyl bromides with ole®ns was more dif®cult and complicated. Further studies showed that an addition±sul®nation reaction occurred when per¯uoroalkyl bromides were allowed to react with ole®ns in aqueous iso-propanol solution. Herein we report the results of this reaction.
played an important role in this reaction. In aqueous isopropanol solution, no byproduct or only trace amount of RFCH2CHBrR was detected, while byproducts such as RFSO2Na and RFCH2CHBrR were formed when CH3CN, C2H5OH, DMF and THF were used as co-solvent in this reaction. The sul®natodebromination reaction of per¯uoroalkyl bromides has been proved to be a radical process in which a per¯uoroalkyl radical was formed as a key intermediate [2]. The fact that a cyclic product was obtained in the reaction of per¯uoroalkyl bromide with diallyl ether indicated that a radical intermediate is involved in the above addition±sul®nation reaction. Thus the following mechanism was proposed:
2. Results and Discussion In the presence of sodium dithionite, per¯uoroalkyl bromides (1) readily reacted with ole®ns in aqueous iso-propanol solution at 60±708C, giving the corresponding addition±sul®nation products (3) in good yields (Scheme 1). The sul®nates were isolated and characterized by converting them to their corresponding sulfonyl chloride (4) with chlorine. The results are listed in Table 1. As shown in Table 1, both ethylene and terminal alkenes with longer chain could react with per¯uoroalkyl bromides to give addition±sul®nation products directly. Solvents
*Corresponding author. Fax: +86-2164-166-128.
The reaction of compound 4 with potassium hydroxide gave the corresponding potassium sulfonate 5 (Scheme 2), a new special and useful hybrid anionic surfactant containing ¯uorocarbon and hydrocarbon chains [4].
0022-1139/99/$ ± see front matter # 1999 Elsevier Science S.A. All rights reserved. PII: S0022-1139(98)00281-4
50
J.-T. Liu et al. / Journal of Fluorine Chemistry 93 (1999) 49±51
Scheme 1.
Table 1 The reaction of perfluoroalkyl bromides with olefins:
using TFA as external standard. The values reported were CFCl3 TFA 76:8 ppm, positive for up®eld shifts. Mass spectra were taken on a Finnegan GC±MS 4021 spectrometer.
Na2 S2 O4
RF Br 1 CH2 CHR 2 ! RF CH2 CH RSO2 Na 3 Cl2
! RFCH2 CH RSO2 Cl 4 Entry
RFBr
Olefin
Product
Yield (%)a
1 2 3 4 5 6 7 8
1a 1b 1c 1c 1d 1d 1d 1d
2b 2b 2a 2d 2a 2b 2c 2e
4ab 4bb 4ca 4cd 4da 4db 4dc 4de
67 69 73 57 64 74 72 65
a
Isolated yields of two steps based on RFBr.
In conclusion, the addition±sul®nation reaction of per¯uoroalkyl bromides and ole®ns has been achieved by initiation with sodium dithionite under mild conditions, providing a facile method for the synthesis of a new type of hybrid anionic surfactant. 3. Experimental IR spectra were measured with a Shimadzu IR-440 spectrometer, using liquid ®lms. 1 H NMR spectra were recorded on a Bruker AM 300 (300 MHz) spectrometer, using TMS as internal standard. 19 F NMR spectra were recorded on a Varian EM-360L spectrometer (56.4 MHz)
Scheme 2.
3.1. Typical procedure A mixture of Cl(CF2)6Br (10 mmol), n-C6H12 (20 mmol), Na2S2O4 (15 mmol) and NaHCO3 (15 mmol) in i-PrOH (15 ml) and H2O (15 ml) was stirred at 708C for 6 h. Then Cl2 was bubbled through the mixture at 0±58C for 5 h. The product was extracted with ether, washed with water and dried over anhydrous Na2SO4. After removal of ether, the crude product was puri®ed by column chromatography on silica gel to give 4db in 74% yield as a colorless liquid. 1 H NMR(300 MHz, CDCl3) 3.88 (m, 1H), 3.15±2.42 (m, 2H), 2.30±1.95 (m, 2H), 1.55 (m, 2H), 1.36 (m, 2H), 0.92 (t, 3H) ppm; 19 F NMR(56.4 MHz, CDCl3) 68.2 (s, 2F), 111.0 (m, 2F), 119.1 (m, 2F), 120.0 (m, 4F), 121.8 (m, 2F) ppm; IR (, cmÿ1) 2964, 2870, 1470, 1440, 1380, 1210, 1160; MS(m/z) 518 (M), 419 (M-SO2Cl); Anal. Calcd for C12H12Cl2F12O2S: C 27.76, H 2.33, Cl 13.65, F 43.91, S 6.18; Found: C 27.63, H 2.27, Cl 13.78, F 44.42, S 6.23%. 4ab: 1 H NMR(300 MHz, CDCl3) 3.88 (m, 1H), 3.15± 2.42 (m, 2H), 2.30±1.94 (m, 2H), 1.58 (m, 2H), 1.38 (m, 2H), 0.92 (t, 3H) ppm; 19 F NMR(56.4 MHz, CDCl3) 80.3 (s, 3F), 112.8 (m, 2F), 121.3±123.0 (m, 6F), 125.8 (m, 2F) ppm; IR (, cmÿ1) 2970, 2930, 2862, 1466, 1365, 1242, 1208, 1148; MS(m/z) 503 (M1), 403 (M-SO2Cl); Anal. Calcd for C12H12ClF13O2S: C 28.67, H 2.40, F 49.13, S 6.38; Found: C 28.47, H 2.76, F 49.55, S 6.25%. 4bb: 1 H NMR(300 MHz, CDCl3) 3.90 (m, 1H), 3.15± 2.44 (m, 2H), 2.30±1.95 (m, 2H), 1.55 (m, 2H), 1.40 (m, 2H), 0.95 (t, 3H) ppm; 19 F NMR(56.4 MHz, CDCl3) 81.0 (s, 3F), 112.2 (m, 2F), 121.7±123.0 (m, 10F), 126.2 (m, 2F) ppm; IR (, cmÿ1) 2963, 2937, 2877, 1466, 1372, 1208, 1152; MS(m/z) 603 (M1), 503 (M-SO2Cl); Anal. Calcd for C14H12ClF17O2S: C 27.90, H 2.01, F 53.58, S 5.32; Found: C 28.20, H 2.02, F 53.25, S 5.23%.
J.-T. Liu et al. / Journal of Fluorine Chemistry 93 (1999) 49±51
4cd: 1 H NMR(300 MHz, CDCl3) 3.88 (m, 1H), 3.14±2.42 (m, 2H), 2.30±1.95 (m, 2H), 1.56 (m, 2H), 1.30 (m, 10H), 0.90 (t, 3H) ppm; 19 F NMR(56.4 MHz, CDCl3) 67.5 (s, 2F), 111.8 (m, 2F), 119.2 (m, 2F), 122.0 (m, 2F) ppm; IR (, cmÿ1) 2930, 2858, 1465, 1430, 1382, 1190, 1138; MS(m/z) 475 (M1), 375 (M-SO2Cl); Anal. Calcd for C14H20Cl2F8O2S: C 35.38, H 4.24, F 31.98, S 6.74; Found: C 35.50, H 4.60, F 32.35, S 6.52%. 4dc: 1 H NMR(300 MHz, CDCl3) 3.90 (m, 1H), 3.15±2.42 (m, 2H), 2.32±1.95 (m, 2H), 1.56 (m, 2H), 1.32 (m, 6H), 0.90 (t, 3H) ppm; 19 F NMR(56.4 MHz, CDCl3) 68.2 (s, 2F), 113.0 (m, 2F), 120.6 (m, 2F), 121.8 (m, 4F), 123.8 (m, 2F) ppm; IR (, cmÿ1) 2930, 2861, 1458, 1432, 1378, 1212, 1152; MS(m/z) 546 (M), 447 (M-SO2Cl); Anal. Calcd for C14H16Cl2F12O2S: C 30.73, H 2.95, F 41.66, S 5.86; Found: C 30.56, H 2.82, F 41.93, S 5.72%. 4de: 1 H NMR(300 MHz, CDCl3) 4.10±3.58 (m, 6H), 3.10±2.90 (m, 2H), 2.18 (m, 2H) ppm; 19 F NMR(56.4 MHz, CDCl3) 67.6 (s, 2F), 113.2 (m, 2F), 120.0 (m, 2F), 121.2 (m, 4F), 123.3 (m, 2F) ppm; IR (, cmÿ1) 2907, 1375, 1200, 1165; MS(m/z) 532 (M), 433 (M-SO2Cl); Anal. Calcd for C12H10Cl2F12O3S: C 27.03, H 1.89, F 42.76, S 6.01; Found: C 27.22, H 1.77, F 42.72, S 6.06%. 3.2. The reaction of perfluoroalkyl bromides with ethylene To a 100 ml-autoclave were added Cl(CF2)4Br (4 mmol), Na2S2O4 (6 mmol), NaHCO3 (6 mmol), i-PrOH (5 ml) and H2O (5 ml). Then ethylene was added and the mixture was stirred at 708C and 8±12 atm for 24 h. Workup as above gave 4ca in 73% yield. 1 H NMR(300 MHz, CDCl3) 3.94 (m,
51
2H), 2.85 (m, 2H) ppm; 19 F NMR(56.4 MHz, CDCl3) 67.8 (s, 2F), 113.0 (m, 2F), 119.8 (m, 2F), 122.4 (m, 2F) ppm; IR (, cmÿ1) 3008, 2942, 1443, 1371, 1192, 1138; MS(m/z) 362 (M), 263 (M-SO2Cl); Anal. Calcd for C6H4Cl2F8O2S: C 19.85, H 1.11, F 41.86, S 8.83; Found: C 19.69, H 1.06, F 41.46, S 8.61%. 4da: 1 H NMR(300 MHz, CDCl3) 3.95 (m, 2H), 2.85 (m, 2H) ppm; 19 F NMR(56.4 MHz, CDCl3) 67.6 (s, 2F), 113.0 (m, 2F), 119.1 (m, 2F), 121.2 (m, 4F), 123.0 (m, 2F) ppm; IR (, cmÿ1) 3008, 2942, 1443, 1371, 1192, 1138; MS(m/z) 462 (M), 363 (M-SO2Cl); Anal. Calcd for C8H4Cl2F12O2S: C 20.75, H 0.87, F 49.23, S 6.92; Found: C 20.41, H 0.78, F 48.91, S 6.91%. Acknowledgements We are grateful to the Chinese Natural Science Foundation for ®nancial support (grant no. 29 772 041). References [1] W.-Y. Huang, B.-N. Huang, W. Wang, Acta Chimica Sinica (Engl. Ed.) (1985) 253. [2] B.-N. Huang, B.-H. Wang, W. Wang, W.-Y. Huang, Acta Chimica Sinica (Engl. Ed.) (1986) 68. [3] W.-Y. Huang, W. Wang, B.-N. Huang, Acta Chimica Sinica (Engl. Ed.) (1986) 178. [4] M. Abe, K. Tobita, H. Sakai, Y. Kondo, N. Yoshino, Y. Kasahara, H. Matsuzawa, M. Iwahashi, N. Momozawa, K. Nishiyama, Langmuir 13 (1997) 2932.