To a suspension of 1,3,9,10,11,12-hexahydro-3-methyl-2H-quino[4,3,2-ef][1,4]benzoxazepin-2-one (5.0 g) in dry dimethylformamide (60 ml) was added potassium t-butoxide (3.15 g), with stirring. After 15 mins, benzyl bromide (2.66 ml) was added, and the reaction mixture was stirred for two hrs. The reaction mixture was diluted with water (300 ml), extracted twice with 100 ml-portions of diethyl ether, dried over anhydrous magnesium sulfate, filtered, and concentrated. The residue was adhered to silica and flash chromatographed (10-30% ethyl acetate/hexane). The mixed fractions were flash chromatographed (3% ethyl acetate/dichloromethane), and the appropriate fractions were combined, and concentrated. Trituration of the residue with (1/1-diethyl ether/pentane) gave 4.58 g (68%) of 1-benzyl-3-methyl-1,3,9,10,11,12-hexahydro-2H-quino[4,3,2-ef][1,4]benzoxazepin-2-one.
