Studies on Quinoline and Isoquinoline Derivatives. VI. Addition Reaction of Diketene with Isoquinolines in the Presence of Carboxylic Acids

Abstract

The addition reaction of diketene in formic, acetic or propionic acid to isoquinoline afforded 1-acetonyl-2-acyl-1, 2-dihydroisoquinoline (II) in satisfactory yields. Though no reaction of this type was observed to occur in quinoline, isoquinoline-like N-heteroaromatic compounds such as phthalazine and 1, 6-naphthyridine underwent similar addition reactions to give the corresponding dihydro-acetonyl compounds. The above product II was easily convertible to benzoquinolizine derivatives.