Polycyclic fused amidines. Part II. Synthesis of dihydroimidazo-fused systems by use of 2-aminoethylammonium toluene-p-sulphonate

Abstract

Heating 2-aminoethylammonium tosylate (EDMT) with various aromatic bicyclic amides at 200–250 °C provides a convenient single-stage synthesis of the corresponding dihydroimidazo-compounds. The procedure worked well with phthalazinones (1), quinolones (7), and isoquinolone, but no reaction occurred with analogous monocyclic pyridazones (12) and 2-pyridone. Only low yields of dihydroimidazo-derivatives were obtained from 3,4-dihydroisoquinoline-1(2H)-thione (10) and indeno[1,2,3-de]phthalazin-3-ones (14). Side reactions dominated the reactions of EDMT with quinoxalinones and benzanilide.