Metabolites of chloroquine: some observations on desethylchloroquine and N-acetyldesethylchloroquine.

ABSTRACT

The major metabolite of chloroquine, (+)-desethylchloroquine, produced by stereoselective N-dealkylation of the drug, was obtained in 81.5% enantiomeric purity by resolution of racemic desethylchloroquine using an atropisomeric resolving agent and was shown by circular dichroism to have the absolute (S)-configuration. The minor metabolite N-acetyldesethylchloroquine was prepared in both the racemic and the (S)-(+)-form.