THE SYNTHESIS OF DIBENZ[a,c][1,3]CYCLOHEPTADIENE - 5,7-DIONE

Abstract

The synthesis of dibenz[a, c][1,3]cycloheptadiene-5,7-dione (I), a new member of the dibenz[a,c][1,3]cycloheptadiene (II) series, has been accomplished by (1) the condensation of diethyl diphenate and ethyl acetate with alkaline catalysts, (2) the reaction of diphenoyl chloride and sodiomalonic ester, and (3) the condensation of diphenic anhydride and malonic ester with zinc chloride. In addition to the (I), these reactions afford comparable amounts of 2,21-diacetyl biphenyl (XIII). It has been possible to establish the identity of (I) from the carbonyl and enolic derivatives and products obtained in reactions of hydrolysis, oxidation, and reduction.