Hydrogen Bromide → H-Thz-NH-tBu

Reaction equation

C(OC([N:11]1[C@H:15]([C:16]([NH:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[CH2:14][S:13][CH2:12]1)=O)C1C=CC=CC=1.Br.C(OCC)C>C(O)(=O)C>[C:19]([NH:18][C:16]([C@@H:15]1[CH2:14][S:13][CH2:12][NH:11]1)=[O:17])([CH3:22])([CH3:20])[CH3:21]

Participants

Procedure

A mixture of 3.2 g of 3-(benzyloxycarbonyl)-N-tert.butyl-4(R)-thiazolidinecarboxamide and 10 ml of 32% (w/w) hydrogen bromide in glacial acetic acid was stirred at room temperature for 2 hours. The resulting solution was poured into diethyl ether and the precipitated hydrobromide salt of the product was filtered off, washed with diethyl ether and then dissolved in water. The solution was made alkaline by the addition of 1M sodium hydroxide solution and extracted twice with dichloromethane. The combined dichloromethane extracts were washed with water, dried over anhydrous sodium sulphate, filtered and evaporated to give 1.57 g of N-tert.butyl-4-(R)-thiazolidinecarboxamide as a crystalline solid of melting point 68°-71° C.