Metabolic pathway by cleavage of a furan ring

14C-Diclofurime, a new Ca antagonist, was administered orally to dogs and pigs, and metabolites detected in urine and plasma. Metabolites contained in pooled urine were concentrated by column chromatography (reverse phase, gel permeation and normal phase). Chemical structures were determined by i.r. mass and 1H n.m.r. spectroscopy. The main route of Diclofurime biotransformation involved cleavage of the furan ring. Subsequent biotransformation steps involved N-deethylation in the side-chain and O-demethylation in the aromatic moiety of the drug. The major pathway is unusual for molecules with a furan heterocycle.