Ultrasound - promoted coupling of heteroaryl halides in the presence of lithium wire. Novel formation of isomeric bipyridines in a Wurtz - type reaction

✍ Scribed by Alan G. Osborne; Kathryn J. Glass; Miriam L. Staley

• Book ID: 104229594
• Publisher: Elsevier Science
• Year: 1989
• Tongue: French
• Weight: 124 KB
• Volume: 30
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)99442-5

✦ Synopsis

Sumzarg Ultrasonic irradiation of 2-bmopyridine in MF solution in the presence of lithium tire gives 2,21-=bipyridine, 2,4'-bipyridfne and 4,4'-bipyridine, a novel formation of isomers in a Wurtz-type reaction. Similar reaction with 3_bromoppridine mainly results in debromination. ?he application of ultrasound to facilitate organic reactions has recently attracted considerable interest. lp2 Biphenyl (&) may be obtained from bromobenzene (1) in 'K$ yield through a Wurtz-type sonochancical coupling reaction with lithium wire in !lHF solution.3'4 Lindley, Iorimer and Mason' have reported that ultrasor&? irradiation of activated aryl halides, w 2-iodonitrobenzene, produced a 50-fold increase in reactivity compared to the classical Ullmann reaction. However, as far as the present authors are a~are,~ applications of the above reactions for the syntheses of bipyridines have not been reported. In connection with our Chaot 3, 4 (19@9)