Preparation of 9H‐Tribenz(b,d,f)azepine and Its 1‐Methoxy Derivative.

Two convenient routes to 9H-tribenz[b,d,f]azepine (2) have been developed. The first method involves the deoxygenation and hydrolysis of 1,4-dihydro-1,4-epoxy-9-acetyl-9H-tribenz[b,d,f]azepine (8) employing low-valent titanium. The second method employs the reactive intermediate 10,11-didehydro-5-acetyl-5H-dibenz[b,f]azepine (7) in a Diels-Alder reaction with 1,3-cyclohexadiene. The resulting cycloadduct 13 upon undergoing a retro-Diels-Alder reaction and hydrolysis yields 2. 1-Methoxy-9H-tribenz[b,d,f]azepine (11) was prepared from ring opening of 8 to 1-hydroxy-9-acetyl-9H-tribenz[b,d,f]azepine (10) followed by methylation with dimethyl sulfate and hydrolysis