Synthesis of (pyridinyl)-1,2,4-triazolo[4,3-<i>a</i>]pyridines
作者:Daniel B. Moran、George O. Morton、J. Donald Albright
DOI:10.1002/jhet.5570230422
日期:1986.7
4-triazolo[4,3-a]pyridines were developed. The principal route to the required intermediate 2-chloropyridines was based on rearrangements of mono N-oxides of 2,2′-bipyridine, 2,3′-bipyridine, 3,3′-bipyridine, 2,4′-bipyridine and 4,4′-bipyridine with phosphorus oxychloride. Reaction of 3,3′-bipyridine 1-oxide or 2,2′-bipyridine 1-oxide with phosphorus oxychloride gave mixtures of chloro isomers. Reaction with acetic