ChemInform Abstract: Derivatives of the Benzo(5,6)cyclohepta(1,2,3-cd)thieno(3,2-c)pyridine System. X-Ray Crystal Structure of 8,9-Dimethoxy-1,2,3,6,11,11a-hexahydrobenzo(5,6)cyclohepta(1,2,3-cd)thieno(3,2-c)pyridine-1-carbonitrile

ChemInform Abstract

(IIIb). - Reduction of the Bischler-Napieralski product from the reaction of (I) with POCl₃ does not lead to the desired quinolizine (IV). Instead, the ethoxymethyl derivative (II) is formed. Protonation of (II) fails as well to give (IV), instead the new heterocycle (IIIa) is obtained which is both methylated to (IIIc) and reacted with BrCN to give (IIIb) (space group P2₁/c with Z=4). The latter (IIIb) is also obtained independently from (IV).