Novel crystalline forms of 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-a, a-dimethylbenzene acetic acid and its hydrochloride

A technology of hydroxydiphenylmethyl and dimethylphenylacetic acid, applied in the field of novel anhydrous crystalline form X, can solve problems such as increasing production cost

Inactive Publication Date: 2008-05-28
DR REDDYS LAB LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Removal of impurities increases production costs

Method used

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  • Novel crystalline forms of 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-a, a-dimethylbenzene acetic acid and its hydrochloride
  • Novel crystalline forms of 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-a, a-dimethylbenzene acetic acid and its hydrochloride
  • Novel crystalline forms of 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-a, a-dimethylbenzene acetic acid and its hydrochloride

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0063] Preparation of Pure Fexofenadine

[0064] A solution of crude Fexofenadine (500 g; prepared according to Reference Example) in methanol (4000 ml) was refluxed for 1 hour and the reaction mixture was then cooled to room temperature. The resulting precipitated pure Fexofenadine was filtered and washed with methanol (250ml). Repeated recrystallization in methanol afforded pure Fexofenadine with the desired purity.

[0065] HPLC purity 99.85%; meta-isomer <0.1%

Embodiment 2

[0067] step 1

[0068] Preparation of Form A from pure Fexofenadine

[0069] A suspension of pure Fexofenadine (180 g) in toluene (1800 ml) was azeotropically refluxed for 2.5 hours. The reaction mixture was then cooled to room temperature and stirred for about 40 minutes. After completing this step, the reaction mixture was filtered and washed with toluene (180 mL) and the resulting Fexofenadine Form A was dried at 80-85° C. at atmospheric pressure until constant weight.

[0070] Yield 179.2 g: M.R (melting point range) 220-224°C.

[0071] step 2

[0072] Preparation of Fexofenadine Hydrochloride in Form X

[0073] To Fexofenadine Form A (170 g; prepared as in Step 1 ) was added toluene (1700 ml) followed by slow addition of isopropanol hydrogen chloride (made by passing hydrogen chloride through isopropanol) to pH 2. The reaction mass was then stirred for 10 hours and 15 minutes. The resulting solid was filtered, washed with toluene (170ml) and dried under vacuum at 75...

Embodiment 3

[0076] Preparation of Fexofenadine Hydrochloride in Form X

[0077] To Fexofenadine Form A (95 g; prepared according to the procedure of Example 2, step 1 ) was added toluene (950 ml) followed by slow addition of isopropanol hydrogen chloride (made by passing hydrogen chloride through isopropanol) to pH 2. The reaction mass was then stirred for 2 hours and 45 minutes. The reaction mass was filtered and washed with toluene (95ml), the solid was isolated and dried at 80-85°C under atmospheric pressure to constant weight.

[0078] A portion of the solid obtained above was kept in an oven at 141-149° C. under 100-mbar pressure for 3.5 hours to remove residual organic solvent to give the desired Form X of Fexofenadine hydrochloride. M.R. 183-188°C.

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Abstract

The present invention is related to novel polymorph of Fexofenadine and Fexofenadine hydrochloride of formula 1 and process of preparation thereof. The present invention is also directed to provide pure novel polymorphs of Fexofenadine and its hydrochloride by a simple process which is cost effective, commercially viable and environment friendly.

Description

field of invention [0001] The present invention relates to a novel crystalline form of fexofenadine hydrochloride and a process for its preparation. More specifically, the present invention relates to a novel anhydrous crystalline Form X of fexofenadine hydrochloride. The present invention also relates to a novel crystalline form of fexofenadine, in particular form A of fexofenadine, and to a process for its preparation. Background of the invention [0002] Chemically fexofenadine hydrochloride is 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-α,α-dimethylphenylacetic acid hydrochloride Salt. It is also known as terfenadine carboxylic acid metabolite. It is expressed as Equation 1. [0003] [0004] Formula 1 [0005] Fexofenadine hydrochloride can be used as an antihistamine without causing the adverse effects associated with the administration of terfenadine, including in some patients with liver disease or in patients additionally taking the antifu...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D211/22A61K31/445A61P43/00B01D9/02
CPCC07D211/22A61P1/16A61P11/00A61P11/08A61P37/00A61P37/08A61P43/00
Inventor M·S·雷迪S·T·拉詹U·V·B·拉奥
Owner DR REDDYS LAB LTD
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