Patent ID: 7388023

Claim:
A method of making a compound of formula IV, or a pharmaceutically acceptable salt thereof, wherein R 3 is a hydrogen atom, (C 1 -C 6 )alkyl, (C 3 -C 6 )cycloalkyl, (C 3 -C 6 )cycloalkyl-(C 1 -C 3 )alkyl, phenyl, phenyl-(C 1 -C 3 )alkyl, pyridyl, or pyridyl-(C 1 -C 3 )alkyl, wherein the alkyl and cycloalkyl moieties or substituents are optionally substituted with from one to five fluorine atoms, and the phenyl and pyridyl substituents and the phenyl and pyridyl moieties of the phenyl-(C 1 -C 3 )alkyl and the pyridyl-(C 1 -C 3 )alkyl substituents are optionally substituted with from one to five substituents independently selected from chloro, fluoro, amino, nitro, cyano, hydroxy, (C 1 -C 3 )alkylamino, (C 1 -C 3 )alkyl optionally substituted with from one to three fluorine atoms, and (C 1 -C 3 )alkoxy optionally substituted with from one to three fluorine atoms, the method comprising: treating a compound of formula 39, with an acid to give a hydrolysis product; and optionally treating the hydrolysis product with an acid or base to give the compound of formula IV or a pharmaceutically acceptable salt thereof, wherein R 3 in formula 39 is as defined for formula IV, and R 13 and R 15 in formula 39 are each independently selected from (C 1 -C 6 )alkyl, (C 3 -C 6 )cycloalkyl, and (C 3 -C 6 )cycloalkyl-(C 1 -C 3 )alkyl.