SYNTHESIS AND MOLECULAR STRUCTURE OF 2,3,4,5-TETRAHYDRO-1<i>H</i>-3-BENZAZEPINE DERIVATIVES AND DIMETHYL 4-CYANO-2,3,6,7-TETRAHYDRO-1<i>H</i>-3-BENZAZONINE-5,6-DICARBOXYLATE
DOI:
https://doi.org/10.1007/935Keywords:
tetrahydro-3-benzazepines, 2, 3, 6, 7-tetrahydro-1H-3-benzazonine-5, 6-dicarboxylate, quaternary 1, 4-tetrahydroisoquinolinium salts, sigmatropic rearrangementAbstract
A study was carried out on the direction of 1,2,3,4-tetrahydroisoquinolinium quaternary salt rearrangements by the action of base with or without dimethyl acetylenedicarboxylate. These quaternary salts containing a methylene group at the nitrogen atom, are converted in the presence of base through intermediate N-ylides into the Stevens rearrangement products, namely, tetrahydro-3-benzazepines. Upon the addition of dimethyl acetylenedicarboxylate as an electrophilic trap, this diester adds at the carbanion site of the ylide with subsequent recyclization of the piperidine fragment to give a 2-benzazonine derivative with an unusual 4,5-positioning of the olefin bond in the nine-membered heterocycle. An X-ray structural analysis established the molecular structures of 2-cyano-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine and dimethyl 4-cyano-2,3,6,7-tetrahydro-1H-3-benzazonine-5,6-dicarboxylate.
Authors: A. T. Soldatenkov, S. A. Soldatova, J. A. Mamyrbekova-Bekro, G. S. Gimranova, A. V. Malkova, K. B. Polyanskii, N. M. Kolyadina, and V. N. Khrustalev
English Translation in Chemistry of Heterocyclic Compounds, 2012, 48 (9), pp 1332-1339
http://link.springer.com/article/10.1007/s10593-012-1141-9