反应详情

Carbon disulphide (27 ml) was added to a mixture of (1S, 2R )-(+)-norephedrine (5.0 g) and aqueous sodium hydroxide (50 ml of 15% solution) and the mixture stirred for 24 hours. Excess carbon disulphide was evaporated under reduced pressure and the residue poured into water and extracted with ethyl acetate. The extracts were washed with water, dried and evaporated. The residue was chromatographed on silica gel (eluent-ether/hexane; 1:1) to give 4-methyl-5-phenylthiazolidine-2-thione and 4-methyl-5-phenyloxazolidine-2-thione. A solution of the first of these thiones (0.80 g) in dimethylformamide was treated with sodium hydride (0.12 g of 80% dispersion in oil). When hydrogen evolution had ceased, intermediate A (1.2 g) was added, over one hour, and the mixture allowed to stand for 60 hours. The mixture was poured into water and extracted with ether. The extract was worked up in conventional manner to give methyl (E)-2-[2-[[(4-methyl-5-phenylthiazol-2-in-2-yl)thio]methyl]phenyl]-3-methoxy-2-propenoate, as a gum. (Compound 1).

1. customExcess carbon disulphide was evaporated under reduced pressure
2. additionthe residue poured into water
3. extractionextracted with ethyl acetate
4. washThe extracts were washed with water
5. customdried
6. customevaporated
7. customThe residue was chromatographed on silica gel (eluent-ether/hexane; 1:1)