To a stirred solution of 0.39 g of 10,11-dihydrodibenz[b,f][1,4]-oxazepine, 1.1 ml of triethylamine in 5 ml of dichloromethane is added 1.17 g of 6-[(5-fluoro-2-methylbenzoyl)amino]-pyridine-3-carbonyl chloride. The mixture is stirred under argon at room temperature for 16 hours, and diluted with 50 ml of dichloromethane and 20 ml of water. The organic layer is separated, washed with 20 ml each of 1M NaHCO3, brine and dried (Na2SO4). The solution is filtered through a thin pad of hydrous magnesium silicate and the filtrate is concentrated to dryness under vacuum. The residue is chromatographed on silica gel with ethyl acetate-hexane (1:1) as solvent to give a solid. Crystallization from ethyl acetate gives 0.335 g of off-white crystals, m.p. 180°-186° C.
