6110
M. Dewan et al. / Tetrahedron Letters 51 (2010) 6108–6110
Table 2
References and notes
Effect of various solventsa,b
1. Joseph, T.; Sahoo, S.; Halligudi, S. B. J. Mol. Catal. A: Chem. 2005, 234, 107.
Entry
Solvent
Reaction time (h)
Yield (%)
2. Consorti, C. S.; Suarez, P. A. Z.; de Souza, R. F.; Burrow, R. A.; Farrar, D. H.; Lough,
A. J.; Loh, W.; da Silva, L. H. M.; Dupont, J. J. Phys. Chem. B 2005, 109, 4341.
3. Li, W. J.; Zhang, Z. F.; Zhang, J. L.; Han, B. X.; Wang, B.; Hou, M. Q.; Xie, Y. Fluid
Phase Equilib. 2006, 248, 211.
4. Gao, Y.; Zhao, X.; Dong, B.; Zheng, L.; Li, N.; Zhang, S. J. Phys. Chem. B 2006, 110,
8576.
1
2
3
4
5
DMF
Ethylacetate
DMSO
[bmim][BF4]
Acetonitrile
14
10
15
3
45
75
49
95
87
9
5. Wang, S. F.; Chen, T.; Zhang, Z. L.; Pang, D. W.; Wong, K. Y. Electrochem.
Commun. 2007, 9, 1709.
a
Reaction condition: 10 mmol of benzaldehyde and 10 mmol of mercaptoacetic
6. Charkrabarty, D.; Seth, D.; Chakraborty, A.; Sarkar, N. J. Phys. Chem. B 2005, 109,
5753.
7. Bomparola, R.; Caporali, S.; Lavacchi, A. Surf. Coat. Technol. 2007, 201, 9485.
8. Anderson, J. L.; Ding, J.; Welton, T.; Armstrong, D. W. J. Am. Chem. Soc. 2002, 124,
14247.
acid catalyzed by 1 mmol of molecular iodine in 5 ml ionic liquid at room
temperature.
b
Confirmed by (FT-IR, TLC, 1H NMR and 13C NMR).
9. Earle, M. J.; Seddon, K. R. Pure Appl. Chem. 2000, 72, 1391.
10. Zhou, Y. Curr. Nanosci. 2005, 1, 35.
Table 3
11. Li, W.; Bin, Z.; Yong, Y. Z.; Jun, Z. X.; Duan, W. Q.; Xian, C. L.; Jun, Z. W. Sci. China,
Ser. B: Chem. 2007, 50.
12. Popp, A.; Gilch, A.; Mersier, A. L.; Petersen, H.; Mechlem, J. R.; Stohrer, J. Adv.
Synth. Catal. 2004, 346, 682.
13. Choi, W. B.; Wilson, L. J.; Yeola, S.; Lotta, D. C.; Schinazi, R. F. J. Am. Chem. Soc.
1991, 113, 9377.
Recyclability of ionic liquid
Table 1
entry 1
Run 1
Run 2
95
Run 3
94
Run 4
92
Run 5
90
Yield (%)
95
14. Lotta, D. C.; Schinazi, R. F.; Choi, W. B. Emory University, USA, WO 9214743 A2,
1992; Chem. Abstr. 1993, 118, 22551.
15. Liotta, D. C.; Choi, W. B.; Emory University, USA, WO 9111186 A1, 1991; Chem.
Abstr. 1991, 115, 208463.
16. Yadav, L. D. S.; Rai, A. Carbohydr. Res. 2009, 344, 2329.
17. Yadav, L. D. S.; Rai, V. K.; Yadav, B. S. Tetrahedron 2009, 65, 1306.
18. Uang, B. J.; Po, S. Y.; Hung, S. C.; Liu, H. H.; Hsu, C. Y.; Lin, Y. S.; Chang, J. W. Pure
Appl. Chem. 1997, 69, 615.
19. Yadav, L. D. S.; Yadav, S.; Rai, V. K. Tetrahedron 2005, 61, 10013.
20. Pustovit, Y. M.; Alekseenko, A. N.; Subota, A. I.; Tolmachev, A. A. Chem.
Heterocycl. Compd. 2006, 42.
carbonyl group of the substrate, thereby enhancing the
electrophilicity of the carbonyl carbon. This facilitates the nucleo-
philic reaction of the sulfohydro group of the mercaptoacetic acid.
It also illustrates the enhanced reactivity of the carbonyl substrate
in case of electronic withdrawing groups in the first step and elec-
tron donating groups in the second step. However the results show,
that the reactivity of the substrate is effectively increased in the
cases when we employ electron donating groups, for example, in
the attack of mercaptoacetic acid on anisaldehyde (Table 1, entry
3) and is drastically reduced in cases when electron withdrawing
groups are present, for example, in ortho-, meta-, and para-nitro-
substituted benzaldehydes (Table 1, entry 4–6). The results indi-
cate that the first step, that is, the attack of nucleophilic thiol
group on electrophilic carbon of the carbonyl compound is the rate
determining step in the synthesis of 1,3-oxathiolan-5-one.
The advantage of using ionic liquid is that the products of the
reaction can be extracted into the organic solvent, ethyl acetate
leaving the ionic liquid behind which can be successfully recycled.
These are quite contrary to dipolar aprotic solvents which are dif-
ficult to remove from the product.
21. Ren, Y.; Cai, C. Synth. Commun. 2010, 40, 1670.
22. Liu, C. F.; Zhang, A. P.; Li, W. Y.; Yue, F. X.; Sun, R. C. Ind. Crops Prod. 2010, 31, 363.
23. Hajipour, A. R.; Mostafavi, M.; Ruoho, A. E. Org. Prep. Proced. Int. 2009, 41, 87.
24. Ren, Y.-M.; Cai, C. Tetrahedron Lett. 2008, 49, 7110.
25. General procedure for synthesis of 1,3-oxathiolan-5-ones derivatives. A mixture of
aromatic aldehyde (10 mmol), mercaptoacetic acid (0.7 ml, 10 mmol) and
catalytic amount of iodine (1 mmol) in ionic liquid, 1-butyl-3-
methylimidazolium tetrafluoroborate (5 ml) was stirred for 3 h at room
temperature. The mixture was then extracted thrice with 10 ml of ethyl
acetate and the combined organic extracts were treated with an aqueous
solution of Na2S2O3 (1 M) and washed with saturated solution of NaHCO3.
Drying of the organic layer in vacuum afforded a crude product, which was
then recrystallised with water to yield pure crystalline 1,3-oxathiolane-5-ones.
The ionic liquid residue was washed with hexane and dried in vacuum
resulting in recycled ionic liquid, [bmim][BF4] (Table 3).
Characterization data of some important compounds. 2-Phenyl-1,3-oxathiolan-5-
one (Table 1, entry 1). IR (KBr) m
max: 2974, 2930, 1726, 1474, 1027 cmÀ1.1H
NMR (DMSO-d6/TMS) d: 3.43 (d, 1H, J = 16.4 Hz, CH2), 3.43 (d, 1H, J = 16.4 Hz,
CH2), 5.4 (s, 1H, CH), 7.3–7.7 (m, 5Harom). 13C NMR (DMSO-d6/TMS) d: 38.2,
91.2, 126.9, 128.4, 128.9, 138.3, 171.0.
We have developed a relatively quicker and greener method for
synthesizing 1,3-oxathiolane-5-one under solvent free conditions
using molecular iodine as a catalyst. The efficacy of the reaction
lies in its high yield, ambient conditions of temperature, and recy-
clability of the reaction media, that is, the ionic liquid (Table 3).
2-(4-Chlorophenyl)-1,3-oxathiolan-5-one (Table 1, entry 2). IR (KBr) mmax: 2976,
1718, 1388, 1156 cmÀ1 1H NMR (DMSO-d6/TMS) d: 3.40 (d, 1H, J = 16.4 Hz,
.
CH2), 3.25 (d, 1H, J = 16.4 Hz, CH2), 5.31 (s, 1H, CH), 7.4–7.9 (m, 5Harom). 13C
NMR (DMSO-d6/TMS) d: 38.2, 91.2, 128.8, 130.3, 132.2, 136.4, 175.0.
2-(4-Methoxyphenyl)-1,3-oxathiolan-5-one (Table 1, entry 3). IR (KBr)
mmax: 2960,
1726, 1510, 1340 cmÀ1 1H NMR (DMSO-d6/TMS) d: 3.74 (s, 3H, CH3), 3.41 (d, 1H,
.
16.4 Hz, CH2), 3.28 (d, 1H, 16.4 Hz, CH2), 6.28 (s, 1H, CH), 6.77–7.46 (m, 5Harom).
13C NMR (DMSO-d6/TMS) d: 40.1, 56.0, 91.2, 115.4, 131.1, 133.1, 167.2, 178.0.
Acknowledgments
2-(2,5-Dimethoxyphenyl)-1,3-oxathiolan-5-one (Table 1, entry 6). IR (KBr) mmax
:
2928, 2836, 1701, 1497, 1279 cmÀ1 1H NMR (DMSO-d6/TMS) d: 3.76 (s, 3H, CH3),
.
S.M. and A.K. gratefully acknowledge financial support from the
Department of Biotechnology, Govt. of India (BT/PR8918/NNT/28/
05/2007).
3.88 (s, 3H, CH3), 3.43 (d, 1H, J = 16.4 Hz, CH2), 3.26 (d, 1H, J = 16.4 Hz, CH2), 5.58
(s, 1H, CH), 6.78–7.45 (m, 5Harom). 13C NMR (DMSO-d6/TMS) d: 38.4, 56.3, 81.6,
113.5, 115.5, 124.9, 154.1, 154.8, 174.5.