Patent ID: 7250520

Claim:
A process for preparing a compound of formula I-a: comprising: a) combining an aqueous solution of the compound of formula IV-a: wherein R 3 is C 1-12 aliphatic, C 3-12 alkyl-cycloaliphatic, C 3-12 alkyl-aryl, C 3-12 alkyl-heteroaryl, or C 3-12 alkyl-cycloaliphatic; R 5 is C 1-12 aliphatic, aryl, heteroaryl, C 1-12 alkyl-cycloaliphatic, C 1-12 aliphatic-aryl, C 1-12 aliphatic-heteroaryl or C 1-12 aliphatic-cycloaliphatic; with a compound of formula V-a wherein R 1 and R 2 are each independently C 1-6 aliphatic; in the presence of zinc, dioxane, water, and optionally an additional suitable solvent to form a compound of formula VI b) acylating the compound of formula VI with a suitable acylating agent to form the compound of formula IX and c) hydrolyzing the compound of formula IX under suitable hydrolysis conditions to form the compound of formula I-a.