Patent ID: 7285686

Claim:
An improved process for preparing a compound of the formula which comprises: (a) conducting a solvent-free reaction between a compound of formula and a monohydric alcohol of formula R 4 OH wherein R 4 is C 1 to C 6 alkyl or a dihydric alcohol wherein said dihydric alcohol is selected from the group consisting of ethylene glycol, 1,3-propylene glycol, and 1,2-propylene glycol, in the presence of sulfuric acid; and (b) treating the reaction product with ammonium hydroxide and water to neutralize residual sulfuric acid; wherein R 1 is an electron withdrawing group selected from the group consisting of cyano, alkoxycarboxyl, alkylcarbonyl, aryl, nitro, trifluoromethyl, and sulfonyl; R 2 and R 3 are selected independently from hydrogen, C 1 -C 5 alkyl, C 1 -C 5 alkoxy, trifluoromethyl, halogen, sulfonyl alkyl, alkyamino, amide, ester, aryl-alkyl, and aryl-alkoxy; and X is selected from the group consisting of chlorine, bromine, and iodine; and wherein said improved process results in about 90% yield and about 80% to 99% in purity of said compound of formula I.