Iminocyclophosphamide as a chemically reactive metabolite of cyclophosphamide

Iminocyclophosphamide has been identified among the metabolites produced by incubation of cyclophosphamide with cytochrome P-450 mono-oxygenase immobilized on beaded Sepharose. The reactive imine was trapped by addition of hydrogen cyanide, and the product, 4-cyanocyclophosphamide, was identified by comparison of its chromatographic and mass-spectral properties with those of a synthetic standard. Iminocyclophosphamide was also generated chemically from 4-hydroperoxycyclophosphamide and characterized both by addition of hydrogen cyanide and by reduction with sodium borodeuteride. The synthesis of authentic 4-cyanocyclophosphamide is also reported.