Biphenylenes. Part XXVII. Synthesis of compounds derived from 2-acetylbiphenylene

Abstract

Mild reduction, followed by dehydration, of 2-acetylbiphenylene gave 2-vinylbiphenylene. Treatment of 2-acetylbiphenylene with phosphorus pentachloride gave 2-chloroacetyl-and cis-dichlorovinyl-biphenylene; some transformations of these compounds are described. Friedel–Crafts acetylation of 2-methylbiphenylene gave mainly the 3-acetyl and 3,7-diacetyl derivatives. Friedel–Crafts acylation of biphenylene with ethoxalyl chloride could be made to give either the 2-glyoxylic ester or a mixture of the mono ester and the 2,6-diglyoxylic ester. Appropriate reduction of biphenylene-2-glyoxylic acid gave the acetic acid and the α-hydroxyacetic acid.

With sulphuric acid 2-acetylbiphenylene gave the 6-sulphonic acid which with bromine gave 6-bromo-2-tribromoacetylbiphenylene. Condensation of 2-acetyl- and 2,6-diacetyl-biphenylene with furfural gave the corresponding furfurylidene derivatives, some reactions of which are described. Some heterocyclic compounds derived from 2-acetylbiphenylene have been prepared.