Collect. Czech. Chem. Commun. 1987, 52, 233-241

Reactions in the series of substituted isoindolo[1,2-b][3]-benzazepin-5-ones

Zdeněk Veselý, Jiří Holubek and Jan Trojánek

Research Institute for Pharmacy and Biochemistry, 194 04 Prague 9


In the reaction of 10,11-methylenedioxy-3,4,12-trimethoxy-7,8-dihydro-5H-isoindolo[1,2-b][3]-benzazepin-5-one (V) with benzyl alcohol and sodium benzyloxide nucleophilic substitution of the 4-methoxy group for benzyloxy group takes place under formation of 4-benzyloxy-3,12-dimethoxy-10,11-methylenedioxy-7,8-dihydro-5H-isoindolo[1,2-b][3]-benzazepin-5-one (VI). An analogous exchange converts compound V in the presence of corresponding alkoxides and alcohols to compounds VII-X. When reducing compound V with sodium dihydridobis(2-methoxyethoxy)aluminate the unstable base XI is formed which on reaction with trifluoroacetic acid gives the red trifluoroacetate XII. As a side product 3,12-dimethoxy-10,11-methylenedioxy-7,8-dihydroisoindolo[1,2-b][3]-benzazepin-5-one (XIII) is formed at the stage of the reduction of the nucleophilic substitution of the 4-methoxy group with the hydride anion. The reaction of compound V with various Grignard reagents always leads to the same product of phenolic character. Its structure XIV was confirmed by comparison of its mass spectra with those of the product of hydrogenolysis of compound VI. Compound VI and the product of benzylation of compound XIV were also identical.