POLYMORPHS OF NITROFURANTOIN .1. PREPARATION AND X-RAY CRYSTAL-STRUCTURES OF 2 MONOHYDRATED FORMS OF NITROFURANTOIN

The preparation and X-ray crystal structures of two monohydrates of th e antibacterial drug nitrofurantoin are reported. Monohydrate I crysta llizes in the monoclinic space group P2(1)/n and monohydrate II in the orthorhombic space group Pbca. The nitrofurantoin molecule maintains the same, planar conformation in both crystals. The molecular packing arrangements in I and II are distinctly different, I possessing a laye r structure while in II the packing is based on a herring-bone motif. Hydrogen bonds of the type O-H...O, N-H...O, O-H...N and C-H...O stabi lize the crystal structures.