To a solution of lithium aluminum hydride in tetrahydrofuran (1M, 11.99 ml) and dry tetrahydrofuran (30 ml) was added aluminum chloride (1.6 g) in portions, with stirring. After five mins, 3-ethyl-1,3,9,10,11,12-hexahydro-1-methyl-2H-quino[4,3,2-ef][1,4]benzoxazepin-2-one (3.55 g) was added, and stirring was continued for 0.5 hr. Ethyl acetate (200 ml) and 10% sodium hydroxide solution (200 ml) were added, the organic layer was separated, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated. The residue was flash chromatographed (1.5% triethylamine/toluene). The appropriate fractions were concentrated and the residue was treated with fumaric acid followed by recrystallization from methanol to give 1.82 g (38%) of product, mp 243° C. (dec.).
