Racemic, (S)-(+)- and (R)-(−)- enantiomers of 13C(6)-labelled PQ (MW 259.1317 g/mol); PQ alcohol, 2-, 3-, and 4-hydroxyprimaquine and CPQ were synthesized as previously reported [9, 22–24]. The identity of the compounds synthesized was confirmed by spectral infra-red (IR), nuclear magnetic resonance (NMR), high-resolution mass spectrometry and physical data in comparison with published values.