To a solution of 3-methyl-4-({1-[3-(trifluoromethyl)phenyl]-1H-tetrazol-5-yl}methyl)-2-piperazinone (75 mg, 0.220 mmol, Compound 32), in N,N-Dimethylformamide (DMF) (1 mL) was added 2-iodopropane (0.024 mL, 0.242 mmol) and sodium hydride (8.81 mg, 0.220 mmol). The resulting reaction mixture was stirred at room temperature for 24 hours. To the reaction mixture was added 1 equivalent of 2-iodopropane and 0.5 equivalent of sodium hydride and stirred for an additional 24 h at room temperature. The reaction mixture was diluted with ethyl acetate (20 mL) and washed with 2N NaOH solution (10 mL). The aqueous phase was extracted with ethyl acetate (2×10 mL). All of the organic phases were combined, dried over magnesium sulphate, filtered and concentrated. The crude product was purified by MDAP. The relevant fractions were combined, concentrated and dried to give the title compound as a colourless oil (8 mg).
