GB586004A - Improvements in or relating to the production of sulphur-containing organic compounds - Google Patents

Abstract

Compounds of the general formula <FORM:0586004/IV/1> wherein R, R1 and R2 may be the same or different alkyl, or aralkyl groups, R1 and R2 may be hydrogen, R3 is an acylamino group and R may carry substituents produced by effecting the reaction of a compound of the general formula <FORM:0586004/IV/2> wherein R1 and R2 have the significance as above or represent H and wherein R5 may be an aryl group or a saturated or unsaturated aralkyl or alkyl group, with a salt-advantageously an alkali metal salt-of a substituted or unsubstituted S-alkyl or S-aralkyl derivative of thiosulphuric acid, thus obviating use of the free mercaptan. Reaction is carried out in the presence of one or more acids, conveniently at room temperature, but also at lower or higher temperatures and in an an anhydrous or somewhat aqueous medium, depending on the nature of the requisite products, water being necessary to effect completion of the reaction. In examples: (1) 2 - phenyl - 4 - isopropylideneoxazolone - 5 and sodium S-benzylthiosulphate, in glacial acetic acid containing acetic anhydride, is saturated in the cold with dry hydrogen chloride and set aside at room temperature for 3 days, prior to evaporating to isolate N-benzoyl-S-benzyl-b b -dimethylcysteine; (2) 2 - phenyl - 4 - isopropylideneoxazolone-5 and sodium S-benzylthiosulphate in slightly aqueous acetic acid containing anhydrous oxalic acid is stood at room temperature for 3 days, evaporated and the ether extract treated with water to isolate crude N-benzoyl-S-benzyl-b b -dimethylcysteine; (3) 2 - methyl - 4 - isopropylideneoxazolone - 5 in slightly aqueous acetic acid, and sodium S-benzylthiosulphate are added successively to anhydrous oxalic acid in glacial acetic acid, maintaining the mixture at room temperature during 3 days, prior to isolating crude N-acetyl-S-benzyl-b b -dimethylcysteine, by adding water and ether-extracting the product.