Patent ID: 8198442

Claim:
A method for preparing a compound of Formula 1 or 1a wherein R 1 is optionally substituted cyclopropyl or an optionally substituted phenyl; comprising the steps of : (1) contacting a mixture comprising (a) a compound of Formula 2a wherein M is alkali metal and R 2 and R 3 are independently C 1 -C 4 alkyl, (b) a C 1 -C 4 alkanol, and (c) a first portion of water, with a solution comprising a first base and a second portion of water, said base being in an amount sufficient to create a first resultant solution having a pH ranging from about 10 to about 14, said first resultant solution comprising a compound of Formula 2b, wherein M and R 3 are defined as above for Formula 2a; (2) contacting the first resultant solution comprising the compound of Formula 2b with a compound of Formula 3 or an acid salt thereof or with a solution comprising a compound of Formula 3 or an acid salt thereof, wherein R 1 is defined as above for Formula 1, and a second base in an amount sufficient to create a second resultant solution having a pH ranging from about 9 to about 12, said second resultant solution comprising a salt of the compound of Formula 1; and (3) adding an acid to the second resultant solution comprising the salt of the compound of Formula 1 to form the compound of Formula 1.