反应详情

A mixture of 4-benzylisothiazolidin-3-one 1,1-dioxide 4 (0.9 g; 4 mmol), chloromethyl phenyl sulfide (0.63 g; 4 mmol) and triethylamine (0.40 g; 4 mmol) in dry acetonitrile (10 mL) was refluxed for 2 h. The solvent was removed in vacuo and the residue was dissolved in methylene chloride and extracted with water (50 mL) 5% hydrochloric acid (50 mL) and 5% sodium bicarbonate (50 mL). The organic layer was dried and evaporated, leaving a crude product (0.8 g) which was purified by flash chromatography (silica gel/hexane:methylene chloride), yielding 0.32 g of 4-benzyl-2-(1-Phenylthiomethyl)isothiazolidin-3-one 1,1-dioxide. This was oxidized to compound 10 by stirring overnight with m-chloroperbenzoic acid (2.2 eq) in methylene chloride. Compound 10 was obtained by evaporating off the solvent, adding ether and collecting the precipitated product, mp 137°-8° C. (0.38 g; 90% yield). 1H NMR: δ 2.85(m, 1H), 3.3(m,2H), 3.5(m,2H), 4.87(s,2H), 7.15(dd,2H), 74.0-7.25(m,3H), 7.81-7.70(m,3H), 8.0(m,2H).

1. temperaturewas refluxed for 2 h
2. customThe solvent was removed in vacuo
3. dissolutionthe residue was dissolved in methylene chloride
4. extractionextracted with water (50 mL) 5% hydrochloric acid (50 mL) and 5% sodium bicarbonate (50 mL)
5. customThe organic layer was dried
6. customevaporated
7. customleaving a crude product (0.8 g) which
8. customwas purified by flash chromatography (silica gel/hexane:methylene chloride)