CRYSTAL AND MOLECULAR STRUCTURE OF 2-OXO-BIS(2-β-CHLOROETHYLAMINO)-4,6-DIMETHYL-1,3,2-OXAZAPHOSPHORINANE: AN ANALOGUE OF CYCLOPHOSPHAMIDE

Abstract

The isomer of the title compound chosen for determination of its crystal and molecular structure by x-ray means has been found to possess an axial mustard group and an equatorial phosphoryl oxygen. This contrasts the phosphorus stereochemistry in cyclophosphamide in which these groups are interchanged. As a consequence of forcing the mustard group into the axial position in the title compound, the C₂N plane of this moiety is positioned such that neither of the pendant ClCH₂CH₂ groups are under the ring. The rotomeric conformation of this group differs from that in cyclophosphamide wherein the mustard C₂N plane is perpendicular to the OPN plane in the ring.