Chloroquine (/ˈklɔrəkwɪn/) is a 4-aminoquinoline drug used in the treatment or prevention of malaria. History Chloroquine (CQ), N'-(7-chloroquinolin-4-yl)-N,N-diethyl-pentane-1,4-diamine was discovered 1934 by Andersag and co-workers at the Bayer laboratories who named it "Resochin". It was ignored for a decade because it was considered too toxic for human use. During World War II United States government-sponsored clinical trials for anti-malarial drug development showed un… (More on Chloroquine)