4-Thiazolidinecarboxylic acid, 2-ethyl- → 3-(3-Acetylthio-2-methylpropanoyl)-2-ethyl-4-thiazolidinecarboxylic acid
Reaction equation
[C:1]([S:4][CH2:5][CH:6]([CH3:10])[C:7](Cl)=[O:8])(=[O:3])[CH3:2].[CH2:11]([CH:13]1[NH:17][CH:16]([C:18]([OH:20])=[O:19])[CH2:15][S:14]1)[CH3:12]>[OH-].[Na+]>[C:1]([S:4][CH2:5][CH:6]([CH3:10])[C:7]([N:17]1[CH:16]([C:18]([OH:20])=[O:19])[CH2:15][S:14][CH:13]1[CH2:11][CH3:12])=[O:8])(=[O:3])[CH3:2]Participants
4
Procedure
3-Acetylthio-2-methylpropanoic acid chloride (5.4 g. prepared from 3-acetylthio-2-methylpropanoic acid and thionyl chloride, b.p. 80°) and 2 N sodium hydroxide (15 ml.) are added to a solution of 2-ethyl-4-thiazolidinecarboxylic acid [Z. Naturforschg, 17b, 765 (1962)] (5.2 g.) in normal sodium hydroxide (30 ml.) chilled in an ice-water bath. After three hours stirring at room temperature, the mixture is extracted with ether, the aqueous phase is acidified and extracted with ethyl acetate. The organic phase is dried over magnesium sulfate and concentrated to dryness in vacuo to yield 3-(3-acetylthio-2-methylpropanoyl)-2-ethyl-4-thiazolidinecarboxylic acid.