Condensation of N-(p-nitrobenzyl)-10,10-dimethyl-9,10-dihydro-10-sila-2-azaanthracene bromide and its 9-oxo derivative with acetylenedicarboxylic ester

Carbanions derived from N-(p-nitrobenzyl)-dihydrosilaazaanthracene condense with acetylenedicarboxylic ester to form substituted silanaphthoindolizines and silaazaaceanthrenes. The analogous salt of the 9-oxo derivative gave the oxo substituted silanaphthoindolizine. The compounds obtained were subjected to reduction, hydrolysis, and opening of the sila-ring.