Method for the production of crystalline forms and crystalline forms of optical enantiomers of modafinil
AssigneeCephalon France
InventorsOlivier Neckebrock, Pierre Leproust
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Abstract
The invention relates to a process for the preparation of crystalline forms of the optical enantiomers of modafinil, comprising stages comprising: i) dissolving one of the optical enantiomers of modafinil in a solvent other than ethanol, ii) crystallising the modafinil enantiomer, iii) recovering the crystalline form of the modafinil enantiomer so obtained. The invention also relates to a process for the preparation of the optical enantiomers of modafinil.
Claims10
A laevorotatory enantiomer of modafinil in a polymorphic form that produces a powder X-ray diffraction spectrum comprising intensity peaks at the interplanar spacings:
- 8.54, 4.27, 4.02, 3.98 (Å).
A laevorotatory enantiomer of modafinil in a polymorphic form that produces a powder X-ray diffraction spectrum comprising reflections at 15.4, 31.1, 33.1 and 33.4 degrees 2θ.
A Form I polymorph of (−)-modafinil.
A process for preparing a Form I polymorph of (−)-modafinil comprising the steps of:
- (a) providing a solution of (−)-modafinil dissolved in a hot solvent;
- (b) rapidly cooling the solution from step (a) to produce crystals;
- (c) filtering the crystals;
- (d) drying the crystals;
- and
- (e) obtaining the crystals of said Form I polymorph of (−)-modafinil, wherein the solvent of step (a) is selected from water, methanol, absolute ethanol, absolute ethanol plus 3% water (v/v), and ethanol denatured with toluene plus 3% water, (v/v, based on the total volume of ethanol and toluene).
Dependencies are inferred from the claim text.