While continuing work on synthesis and study of novel β-carboline systems [1, 2], we obtained 4-phenyl-3, 4-dihydro-β-carboline (2)(a representative of the previously undescribed group of 4-aryl-substituted 3, 4-dihydro-β-carbolines) by formylation of β- phenyltryptamine (1) followed by cyclization under Bischler–Napieralski reaction conditions. In contrast to known derivatives of this series, which are readily formed when the ...