Synthese von Benzofuranen durch Cyclodehydrierung von Phenylmalonylheterocyclen

摘要

Phenylmalonyl heterocyclic compounds such as the quinolones1a–c or3, benzoquinolizinones6a, band the phenalenones8a, bcan be converted to benzofuranes (2a–c, 7a, band9a, b) by cyclodehydrogenation with Pd/C in boiling diphenyl ether. 2-Phenylchinchonic acid (10) reacts under the same conditions to the dimeric benzofuroquinoline12: the decarboxylated quinoline11however gives the monome