To a solution of methyl 2-(2-(cyclohexyl(methyl)amino)-4-methyl-6-p-tolylpyrimidin-5-yl)pentanoate (61 mg; 0.15 mmol) in methanol (1.5 mL) was added a 10 N sodium hydroxide solution (149 μL; 1.489 mmol) and the mixture was heated at 100° C. for 18 h. The volatiles were removed under reduced pressure and the mixture was acidified by adding 6N hydrochloric acid. The suspension was extracted twice with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulphate and concentrated under reduced pressure. The compound was precipitated from a mixture of ethyl acetate and heptane and the formed solid was triturated with heptane to give 40 mg (68%) of the title compound as a white solid. ESI/APCI(+): 396 (M+H). ESI/APCI(−): 350 (M−CO2H); 394 (M−H).
