Biphenylenes. Part XIV. Synthesis of 1- and 2-phenyl-, 2,7-dimethyl-, and 2,3,6,7-tetramethyl-biphenylene

Abstract

1- and 2-Phenylbiphenylene have been made from 1- and 2-lithiobiphenylene, respectively, by treatment with cyclohexanone followed by dehydration and dehydrogenation. 2-Phenylbiphenylene has also been made by pyrolysis of 4- and 5-phenyl-biphenylene-2,2′-iodonium iodide with cuprous oxide.

One new synthesis of 2,7-dimethyl- and two new syntheses of 2,3,6,7-tetramethyl-biphenylene are described.