Patent ID: 6624313
Filing Date: 2003-09-23
Classification: C07D

Abstract:
A process of preparing a compound in crystalline form having the formula I: or an optical isomer or optically active mixture of two or more stereoisomers thereof, whereinAr1 and Ar2 are phenyl; R1 is hydrogen, hydroxy, C1-C4 alkyl, C1-C4 alkoxy or OY wherein Y is a hydroxy protecting group; and R2 and R3 are independently selected from hydrogen and C1-C4 alkyl; which comprises (a) treating a compound having the formula II: wherein Ar1, Ar2, R1, R2, and R3 are as defined above and R4 is C1-C4 alkyl(C&boxH;O)â€”, aryl(C&boxH;O)â€”, NH2(C&boxH;O)â€”, tri(C1-C4 alkyl)silyl, or triarylsilyl, and having the same stereochemical configuration at the corresponding chiral centers as the compound of formula I, with a base in the presence of an alkyl alcohol at âˆ’30 to 100Â° C., for 30 minutes to 24 hours, (b) neutralizing with a carboxylic acid and (c) isolating in crystalline form the compound of formula I.