Patent ID: 7102020

Claim:
A method for preparing a compound of formula (1) comprising: (a) condensing a compound of formula (2): wherein R′ is a carboxylic acid protecting group, with a compound of formula (3): in the presence of an effective amount of CaCl 2 , N[(C 2 –C 4 )alkyl] 3 and [(C 1 –C 4 ) alkyl]OH and microwave irradiation to yield a compound of formula (4): wherein R, X, Y, and Z each independently comprise a moiety selected from hydrogen; C 1 –C 27 alkyl optionally straight chain or branched, optionally comprising about 1 to about 4 double bonds; aryl, optionally substituted with about 1 to about 3 alkyl, alkoxy, halo, or N(R a R b ) wherein R a and R b are independently about C 1 to about C 6 -alkyl; about C 1 to about C 6 -alkoxy; heteroaryl; (about C 1 to about C 30 alkyl)-aryl, wherein the alkyl chain is optionally straight chain or branched and may further comprise about 1 to about 4 double bonds and the aryl group is optionally substituted with about 1 to about 3 alkyl, alkoxy, halo, or N(R a R b ) wherein R a and R b are independently about C 1 to about C 6 -alkyl; (about C 1 to about C 30 alkyl)-heteroaryl, wherein the alkyl chain is optionally straight chain or branched and may further comprise about 1 to about 4 double bonds; cyano; carboxyamido; alkoxycarbonyl; alkylcarbonyloxy; alkoxycarbonyloxy; or N(R a R b ) wherein Ra and Rb are independently H, (about C1 to about C6)-alkyl; and (b) optionally removing protecting R′ to yield a compound of formula (1).