1,3-Dipolar character of six-membered aromatic rings. Part XI. 1-Oxido-3-phenylphthalazinium
Abstract
1-Oxido-3-phenylphthalazinium with styrene and with diphenylacetylene gives the expected cycloadducts. However, reactions with dimethyl acetylenedicarboxylate and with phenylacetylene gave in each case three isomeric products, the structures of which have been elucidated. Mechanisms are suggested for their formation and interconversion.