A solution of aqueous 2N NaOH (1.00 ml) is added to a stirred solution of methyl 2,4-dimethyl-3-[[2-methyl-5-(4-oxo-1-piperidyl)benzoyl]amino]benzoate (0.12 g, 304.20 μmol) in THF:MeOH (2 ml:1 ml). After 16 hours at ambient temperature, the organic solvent is removed under reduced pressure and the residue is diluted with water, acidified to pH 6 with 1N HCl, and extracted with ethyl acetate. The organic layers are combined with aqueous layer and concentrated under reduced pressure. The resulting solids are dissolved in acetonitrile/H2O and lyophilized to afford the title compound as an off-white solid (58 mg, 50.12%). Mass spectrum (m/z): 381.2 (M+1).
