N,N-Dimethylaniline → HCID 68686100, compound

To a solution of 10-[(4-bromophenyl)sulfonyl]-10,11-dihydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine of Step A (2.32 g, 5.753 mmol) and N,N-dimethylaniline (1.17 mL, 9.204 mmol) in dry dichloromethane (20 mL) at 0° C. under nitrogen was added dropwise trichloroacetyl chloride (0.96 mL, 8.629 mmol). The ice bath was removed and the reaction mixture stirred at room temperature for 21 hours. The reaction mixture was then washed with 2 M hydrochloric acid (2×100 mL) and water (100 mL), dried over anhydrous magnesium sulfate, and concentrated in vacuo to give an olive foam. Purification by flash chromatography using a solvent gradient of 5-15% ethyl acetate in hexane afforded a cream solid that was recrystallized from diethyl ether/hexane to afford the title compound (1.986 g, 63%) as an off-white crystalline solid, m.p. 182-183 ° C.