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US 2007/0185354 A1Published application
Processes for preparing venlafaxine and venlafaxine hydrochloride of form I
AssigneeKrka, Tovarna Zdravil, D.D., Novo Mesto
InventorSilvo Zupancic
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Abstract
A process for preparing venlafaxine in a high yield as well as processes for producing venlafaxine hydrochloride of form I having a very high polymorphic purity are described.
Claims26
Process for preparing venlafaxine which comprises
- (a) converting a venlafaxine precursors selected from the group of N,N-didesmethyl venlafaxine of formula (I), a salt thereof, spiro venlafaxine of formula (II) and a salt thereof
- to venlafaxine, wherein the conversion is carried out in the presence of a salt of formic acid which is selected from the group of a metal salt or an ammonium salt of formic acid, and
- (b) optionally reacting the venlafaxine with an acid to prepare an acid addition salt of venlafaxine.
Process for preparing venlafaxine hydrochloride of form I, wherein venlafaxine hydrochloride of form I is crystallized from a solution of venlafaxine hydrochloride in an organic solvent which solvent contains isopropyl acetate and/or cyclohexane.
Process for preparing venlafaxine hydrochloride of form I, wherein
- (a) a solution of venlafaxine in an organic solvent is reacted with aequous HCl, and
- (b) the water content of the resulting solution of venlafaxine hydrochloride is adjusted to less than 3% by weight and preferably less than 1.5% by weight, and
- (c) the venlafaxine hydrochloride of form I is crystallized.
Dependencies are inferred from the claim text.