A slurry of 0.330 g of 10,11-dihydro-10-(4-aminobenzoyl)-5H-imidazo[2,1-c][1,4]benzodiazepine in 15 ml of dioxane is stirred and warmed slightly to obtain a nearly complete solution. The reaction mixture is cooled to room temperature and 43 mg of sodium hydride in oil added. The mixture is warmed slightly. Gas evolution stops in a few minutes. The reaction mixture is cooled to room temperature and 153 μl of 2,4-dichlorobenzoyl chloride in 2.5 ml of dioxane added. An additional 3.5 ml of dioxane is added and the reaction mixture stirred at room temperature for 2 days. The volatiles are evaporated in vacuo to a residue which is partitioned between water and chloroform. The organic layer is separated and the aqueous phase extracted with chloroform two more times. The combined organic layers are trated with activated carbon and filtered through MgSO4. The filtrate is evaporated in vacuo to a tan foam which is purified by flash chromatography on silica gel by elution with CHCl3 and 3-7% CH3 OH in chloroform to give 310 mg of tan foam.
