Studies on quinoline and isoquinoline derivatives. VII. Addition reactions of acetic anhydride and active methylene compounds to the carbon-nitrogen double bond of the isoquinoline ring.

Abstract

Acetic anhydride reacted with isoquinoline (IV) itself under reflux to give an addition product, whereas quinoline did not react with acetic anhydride under the same conditions. The structure of the product was determined to be 2-acetyl-1, 2-dihydroisoquinoline-1-acetic acid (V) by means of chemical reactions. Active methylene (or methyl) compounds were observed to react with IV competitively to give the corresponding 1, 2-dihydroisoquinolines when they were heated with IV in acetic anhydride.