Patent ID: 6667404
Filing Date: 2003-12-23
Classification: A61K,A61P,C07C,C07D,C07K

Abstract:
A process for the preparation of a compound of the formula: or an N-protected derivative thereof;wherein R4 and R4a are independently selected from phenyl, thiazolyl and oxazolyl wherein the phenyl, thiazolyl and oxazolyl ring is unsubstituted or substituted with a substituent selected from the group consisting of (i) halo, (ii) loweralkyl, (iii) hydroxy, (iv) alkoxy and (v) thioalkoxy; R6 is hydrogen or loweralkyl; and R7 is thiazolyl, oxazolyl, isoxazolyl or isothiazolyl wherein the thiazolyl, oxazolyl, isoxazolyl or isothiazolyl ring is unsubstituted or substituted with loweralkyl, comprising reacting a compound of the formula: or an N-protected derivative thereof wherein R4a and R4 are as defined above with an acylating compound of the formula: wherein R6 and R7 are as defined above; and L is an activating group for an acylation reaction.