Synthesis of Dibenzo [b, f] cycloprop [d] azepine Derivatives. II. Introduction of a Cyclopropane Ring by the Dichloromethylene Transfer Reaction

抄録

An improved method for the synthesis of 1, 1a, 6, 10b-tetrahydrodibenzo [b, f] cycloprop-[d] azepine (3) was described. Thus, 5H-dibenz [b, f] azepine (1) was formylated and dichloro-cyclopropanated with dichloromethylene generated from chloroform and aqueous sodium hydroxide in the presence of a phase-transfer catalyst to yield 1, 1-dichloro-1a, 10b-dihydrodibenzo [b, f] cycloprop [d] azepine-6 (1H)-carbaldehyde (2). The latter compound and its deformylated product, 1, 1-dichloro-1, 1a, 6, 10b-tetrahydrodibenzo [b, f] cycloprop [d] azepine (5), were reduced to 3 with sodium in liquid ammonia. 5-Acetyl-, 5-carbamoyl, 5-methyl- and 5-(3-chloropropyl)-5H-dibenz [b, f] azepines (6, 8, 11 and 14), when treated with the dichloromethylene, gave the corresponding dichloro-cyclopropanation products and some other products, in which the substituents had reacted simultaneously with dichloromethylene in several fashions. The reduction of 5 under drastic conditions yielded 5, 6, 7, 12-tetrahydrodibenz [b, g]-azocine (20) and 10H-indolo [1, 2-a] indole (21). cis-and trans-1-Chloro-1, 1a, 6, 10b-tetra-hydrodibenzo [b, f] cycloprop [d] azepines (23, R=H and 24, R=H), on the other hand, were the main products of catalytic hydrogenation of 5. Conformational aspects of the N-methyl derivatives 23 (R=CH₃) and 24 (R=CH₃) were discussed.