A Synthesis of 3-Amino-4-hydroxyquinolin-2 (1H)-one Derivatives via Oxazolo [4, 5-c] quinolin-4 (5H)-ones

Abstract

3-Amino-4-hydroxyquinolin-2 (1H)-one compounds (aminocarbostyrils) were synthesized by a reaction of methyl isocyanoacetate with isatoic anhydrides in the presence of 1, 8-diazabicyclo [5, 4, 0] undec-7-ene (DBU), followed by hydrolysis with HCl. The alkylation of oxazolo [4, 5-c] quinolin-4 (5H)-ones which are the intermediates of the aminocarbostyrils and the acylation of aminocarbostyrils were also investigated. Furthermore, a variety of the quinolin-2 (1H)-one analogs showed antiallergic activity.