A solution of 440 mg (1.3 mmol) methyl 2-(ethylsulfanyl)-6-morpholin-4-yl-4-(trifluoromethyl)-pyridine-3-carboxylate in a MeOH/THF mixture (6 ml, 1:1 v/v) was treated with a 2M aq. LiOH sol. (3 ml) and was then stirred at 60° C. for 5 d. After cooling to RT the RM was acidified with a 2M aq. HCl sol. to pH 2. Upon dilution with EtOAc the precipitate formed was filtered off to give 176 mg (0.5 mmol, 42%) 2-(ethylsulfanyl)-6-morpholin-4-yl-4-(trifluoromethyl)-pyridine-3-carboxylic acid, which was used in the next step without further purification.
