Qiang Nie

Effects of Solvent and Impurity on Crystal Habit Modification of 11α-Hydroxy-16α, 17α-epoxyprogesterone

Abstract The effects of solvent and impurity on the crystal habit of 11α-hydroxy-16α, 17α-epoxyprogesterone (HEP) grown from solution were studied by scanning electron microscope. Long prismatic crystals were produced when HEP was crystallized from pure acetone and N, N -dimethylformamide, while blocky crystals were produced from pure chloroform by cooling crystallization. One kind of isomorphic impurity, 16α, 17α-epoxyprogesterone (EP) was selected to examine its effect on the HEP crystal habit. When the content of EP in the mother liquor is very high (55.45%, solvent free basis), the habit of produced HEP crystals was greatly modified from prismatic to octahedral. The differential scanning calorimetry and X-ray powder diffraction analyses showed that the change of crystal habit was originated from the crystal structure modification.

16α,17-Epoxy-4-pregnene-3,20-dione

The title compound, C21H28O3, is a steroid derivative used as an intermediate in medicine. The molecular structure corresponds to an earlier determination [Goubitz et al. (1984). Steroids, 44, 153–158]. However, the orthorhombic unit-cell parameters of the two determinations are significantly different, and these structures are polymorphs.

16α,17-Epoxy­pregn-4-ene-3,11,20-trione

The title compound, C21H26O4, is an important steroid used as an intermediate in the synthesis of hormone pharmaceuticals. No inter- or intramolecular hydrogen bonds were observed in the crystal structure.