Abstract: Primaquine has been synthesized by hydrolysis of the fused product of 6-methoxy-8-aminoquinoline and 4-bromo-1-phthalimidopentane, which has been obtained from 1,4-dibromopentane and potassium phthalimide. The total yield of primaquine diphosphate is 42.5-48.4% (based on the amount of potassium phthalimide used).