Dicyclohexylcarbodiimide → HCID 86750875, compound

Participants

Reaction Steps

B tert-Butyl (4R)-3-(2-tert-butoxycarbonylaminoacetyl)-2-benzyl-4-thiazolidinecarboxylate (isomer A) may be prepared in a manner similar to that described in Example 1C, but starting with 25.7 g of tert-butyl (2RS,4R)-2-benzyl-4-thiazolidinecarboxylate, 13.9 g of 2-tert-butoxycarbonylaminoacetic acid and 16.3 g of N,N'-dicyclohexylcarbodiimide. The crude product is purified by chromatography on silica [eluent: methylene chloride/methanol (99:1 by volume)]. The fractions containing the expected product are pooled and concentrated to dryness under reduced pressure at 40° C. 12.1 g of tert-butyl (4R)-3-(2-tert-butoxycarbonyl-aminoacetyl)-2-benzyl-4-thiazolidinecarboxylate (isomer A) are thereby obtained in the form of a cream-coloured foam, which is used in the subsequent syntheses without further treatment.

Provenance & Evidence