Two convenient and high-yielding preparations of 6,6′-dimethyl-2,2′-bipyridine by homocoupling of 6-bromopicoline

6-Bromopicoline can be reductively homocoupled to provide 6,6'-dimethyl-2,2'-bipyridine in high yield either by an Ni bpy catalysed electrosynthesis or by a catalytic modification of the Ullmann synthesis employing Pd(OAc)(2). Either procedure is operationally simple and represents a considerable improvement over most known syntheses of this important disubstituted bipyridine. (C) 2000 Elsevier Science Ltd. All rights reserved.