Patent ID: 6531596
Filing Date: 2003-03-11
Classification: C07C,C07D

Abstract:
A process for the preparation of a compound of formula (I) where R1 represents hydrogen or lower alkyl group and X represents hydrogen or halogen atom, which comprises:(i) benzylating p-hydroxybenzaldehyde of formula (7) â€ƒto obtain a compound of formula (8), (ii) reacting the compound of formula (8) with an alkyl haloacetate in the presence of a base at a temperature in the range of âˆ’10Â° C. to 60Â° C. to obtain a glycedic ester of formula (9) â€ƒwhere R represents lower alkyl group, (iii) opening up the epoxide group of the glycedic ester of a compound of formula (9) in the presence of a catalyst to obtain a compound of formula (10) â€ƒwhere R is as defined above, (iv) hydrolyzing the compound of formula (10) followed by the resolution of the resultant compound to obtain the (S)-hydroxy compound of formula (11), (v) alkylating the compound of formula (11) in the presence of a base to obtain a compound of formula (12) â€ƒwhere R1 represents hydrogen or lower alkyl, and R2 represents lower alkyl, group, (vi) debenzylating the compound of formula (12) to obtain a compound of formula (13) â€ƒwhere R1 and R2 are as defined above, if desired, (vii) converting the compound of formula (13) to a compound of formula (14) â€ƒwhere X represents halogen atom and all other symbols are as defined above, (viii) reacting either the compound of formula (13) or the compound of formula (14) with phenoxazinyl mesylate of formula (15) â€ƒto obtain a compound of formula (16) â€ƒwhere X represents hydrogen or halogen atom, and R1 and R2 are as defined above, (ix) hydrolyzing the compound of formula (16) â€ƒto obtain a compound of formula (1) as defined above, and if desired, (x) resolving the compound of formula (1).