Studies on Ketene and its Derivatives. V. Reaction of Diketene with Quinoline N-Oxide.

Abstract

Reaction of quinoline 1-oxide with diketene results in the formation of 2-(2-quinolyl)-methyl-6-methyl-4H-pyran-4-one (III) in 20% yield, together with formation of quinaldine as a by-product. Hydrolysis of III gives quinaldine, acetone, carbondioxide and acetic acid. Reaction of III with liquid ammonia affords 2-(2-quinolyl) methyl-6-methyl-4(1H)-pyridone (IV). Treatment of IV with phosphoryl chloride gives 2-(2-quinolyl)-methyl-4-chloro-6-methylpyridine (V). Similarly, 2-(4-chloro-2-quinolyl) methyl-6-methyl-4H-pyran-4-one (VI) is prepared from 4-chloroquinoline 1-oxide in 16% yield. The reaction mechanism is discussed in this report.