A solution of aqueous 1N NaOH (1.08 ml) is added to a stirred solution of ethyl 4-[[6-(4-hydroxy-1-piperidyl)-3-methyl-pyridine-2-carbonyl]amino]-3,5-dimethyl-benzoate (223 mg, 0.541 mmol) in THF:MeOH (4 ml:2 ml). After heating at 40° C. for 12 hours, the organic solvent is removed under reduced pressure and the semi-solid is dissolved in water and acidified to pH 3 with aqueous 1N HCl. The resulting precipitate is filtered, washed with water, and dried at 40° C. in a vacuum oven for 12 hours to give the title compound as a white solid (160 mg, 77%). Mass spectrum (m/z): 384.2 (M+1). Alternative synthesis of 4-[[6-(4-hydroxy-1-piperidyl)-3-methyl-pyridine-2-carbonyl]amino]-3,5-dimethyl-benzoic acid.
