Abstract: Phenylmalonyl heterocyclic compounds such as the quinolones 1a-c
or 3, benzoquinolizinones 6a,b and the phenalenones 8a,b
can be converted to benzofuranes (2a-c, 7a-b and 9a,b) by
cyclodehydrogenation with Pd/C in boiling diphenylether. 2-Phenylchinchonic
acid (10) reacts under the same conditions to the dimeric benzofuroquinoline
12; the decarboxylated quinoline 11 however gives the monomer 13.
Reprint as pdf-file on request