To a solution of 6-{[4-(trifluoromethoxy)phenyl]sulfonyl}-2-(trifluoromethyl)-6,11-dihydro-5H-pyrido[2,3-b][1,5]benzodiazepine-8-carbonitrile (702 mg, 1.365 mmol) in 5 ml of THF was added a solution of methyl magnesium bromide (4.87 ml, 6.82 mmol) in THF (1.4 M) at 0° C. The solution was heated to reflux for 8 h, then the solution was cooled to room temperature. Excess Grignard reagent was decomposed by the addition of 4 mL of 2N HCl and the solution was stirred for 1 hr at rt. The pH was adjusted to 7-8 with aqueous NaHCO3. The resulting solution was filtered and the solids were washed with CH2Cl2. To the filtrate was added 30 mL of CH2Cl2, and the layers were separated. The aqueous layer was extracted with CH2Cl2 (3×20 ml), and the combined organic layers were dried with Na2SO4 and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography on silica gel, eluting with hexane/ethyl acetate (6:1-4:1) to give the title compound as a white solid; Mass Spectrum: m/e=591 (M+1).
