Potential Antimalarials. XV. Di-Mannich Bases of 2-(7'-Chloroquinolin-4'-ylamino)phenol and 2-[7'-Bromo( and trifluoromethyl)-1',5'-naphthyridin-4'-ylamino]phenol

Abstract

A total of 26 di-Mannich base derivatives of 2-(7'-chloroquinolin-4'-ylamino)phenol and 2-[7'- bromo (and trifluoromethyl )-1',5'-naphthyridin-4'-ylino]phenol, such as 2-(7'-chloroquinolin- 4'-ylamino)-4,6-bis( piperidin-1″-ylmethyl )phenol, together with some 3- and 5-methyl derivatives and mono-Mannich analogues, have been prepared by condensation of the 4-chloro heterocycle with the appropriate Mannich base derivatives of 2-aminophenols. In in vitro tests against Plasmodium falciparum, many of the di-Mannich base derivatives of 2-(7'-chloroquinolin-4'-ylarnino)phenol exhibited activity comparable to or superior to chloroquine against the chloroquine -sensitive (FCQ-27) isolate, and vastly superior activity compared with chloroquine against the chloroquine -resistant (K-1) isolate. Strong antimalarial activity was also revealed in in vivo tests against Plasmodium vinckei vinckei in mice.