Formation of benzazepines from indoles by ring expansion with dimethyl acetylenedicarboxylate confirmed by an X-ray structure determination
Abstract
1-Methylindole with dimethyl acetylenedicarboxylate in acetonitrile yields dimethyl 1-methylbenz[b]azepine-3,4-dicarboxylate which adds a further mole of the indole to give the 2,3-dihydro-2-(3-indolyl) derivative, the structure of which has been established by X-ray diffraction.