Patent ID: 7741511

Claim:
A process for preparing a carboxylic acid ester of formula (3): R 2 COOR 1 (3) wherein R 1 is an alkyl group which may be substituted, an alkenyl group which may be substituted, an alkynyl group which may be substituted, an aralkyl group which may be substituted, or a heteroarylalkyl group which may be substituted, and R 2 is an alkyl group which may be substituted, an alkenyl group which may be substituted, an alkynyl group which may be substituted, an aryl group which may be substituted, a heteroaryl which may be substituted, an aralkyl group which may be substituted, or a heteroarylalkyl group which may be substituted, which process comprises the steps of reacting a monohydroxy compound of formula (1): R 1 OH (1) wherein R 1 is as defined above, with a zirconium compound of formula (6): Zr(OR 8 ) 4 (6) wherein R 8 is an alkyl group or an aryl group which may be substituted and is not the same as R 1 , to prepare a zirconium compound of formula (8): Zr(OR 1 ) n (OR 8 ) 4-n (8) wherein R 1 and R 8 have the same meanings as defined above, and n is an integer of 1 to 4, or mixtures thereof, and reacting a carboxylic acid of formula (2): R 2 COOH (2) wherein R 2 is as defined above, with the same monohydroxy compound of formula (1) used above in the presence of the zirconium compound prepared above.