A through-space interaction of 3-benzylthiothieno[3,4-b]indolizine derivatives combined by a highly flexible spacer

Some ethyl 1 -benzoyl-3-[(un)substituted benzylthio]thieno[3,4-b]indolizine-9-carboxylates were prepared and their conformations were investigated. In the solid state and the chloroform solution they had stacked structures in which the phenyl ring and the pyridine moiety of theino[3,4-b]indolizine ring are partly overlapped.