Divergent Pathways for Reactions of 3-Formylchromone with Cyclic Secondary Amines in Alcoholic Media

Abstract

Reaction of 3-formylchromone with cyclic secondary amines in methanol results in (E)-2-methoxy-3-(R 2N-methylene)chroman-4-ones, while use of ethanol leads to (E)-2-morpholino-3-(morpholino­methylene)chroman-4-one or enaminoketones as dihydropyran ring-opening products. The solubility of the formed products in alcoholic media is postulated to be a key factor that determines the reaction pathway.