Process for the preparation of fexofenadine

A technology based on dimethylphenylacetic acid and cyclopropyl ketone, which is applied in the field of intermediates for the preparation of the antihistamine fexofatine, and can solve problems such as difficulties in commercial application, cumbersome processes, and reduced yields

Inactive Publication Date: 2006-03-01
RANBAXY LAB LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0011] Previous methods are not suitable for commercial use due to adverse environmental impact, expensive production and cumbersome processes
Most reagents are unfavorable for production because they lead to runaway reactions that reduce yields and make commercialization of these methods more difficult

Method used

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  • Process for the preparation of fexofenadine
  • Process for the preparation of fexofenadine
  • Process for the preparation of fexofenadine

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preparation example Construction

[0022] The inventors have developed an efficient method for the preparation of cyclopropylketo α,α-dimethylphenylacetic acid by treating 4-[cyclopropylcarbonyl]-2,2-dimethylphenylacetic acid with an alkali metal hydroxide Phenylethyl alcohol, after adding an oxidizing agent, reacts in an acidic aqueous solution; then separates the cyclopropyl ketone group α, α-dimethylphenylacetic acid.

[0023] Generally, an alkali metal hydroxide solution can be prepared by dissolving the alkali metal in water, and treating 4-[cyclopropylcarbonyl]-2,2-dimethylphenethanol with the solution. In addition, the solution can be prepared in a solvent if the alkali metal hydroxide is soluble, including, for example, lower alkanols, ketones, water and mixtures thereof.

[0024] Alkali metal hydroxides include any hydroxide including, for example, lithium hydroxide, sodium hydroxide, and potassium hydroxide.

[0025] Usually, the reaction of 4-[cyclopropylcarbonyl]-2,2-dimethylphenethanol and alkali ...

Embodiment

[0037] Embodiment: the preparation of cyclopropyl keto group α, α-dimethylphenylacetic acid

[0038] To an aqueous solution of sodium hydroxide (11.5 g) was added 4-[cyclopropylcarbonyl]-2,2-dimethylphenylethanol (125 g) at room temperature to obtain a suspension. At room temperature, solid potassium permanganate was added to the suspension in small batches within 4 to 5 hours. After the reaction was complete, acetone (1 mL) was added, the manganese dioxide formed was filtered, and the filtrate was washed with dichloromethane (25 mL+12.5 mL) to remove non-acidic impurities. After the aqueous layer was acidified with hydrochloric acid, the product was isolated to give 23.7 g of high purity product.

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Abstract

The present invention relates to a process for the preparation of cyclopropyl keto alpha,alpha-dimethylphenyl acetic acid of structural Formula I, and to the use of this compound as an intermediate for the preparation of an antihistamine, fexofenadine.

Description

technical field [0001] The field of the present invention relates to the preparation method of cyclopropyl ketone α, α-dimethylphenylacetic acid shown in structural formula I, and the use of the compound as an intermediate for the preparation of antihistamine fexonatin. [0002] [0003] Formula I Background of the invention [0004] Chemically, fexonatin is 4[1-hydroxyl-4-[4-(hydroxybenzhydryl)-1-piperidinyl]butyl]-α,α-xylyleneacetic acid (formula II), And known from US Patent No: 4,254,129. It is one of the most widely used antihistamines, used to treat allergic reactions. [0005] [0006] Formula II [0007] Generally, the synthesis methods reported in the literature for the preparation of cyclopropylketo α,α-dimethylphenylacetic acid involve the treatment of alcohols of formula III with conventional oxidizing agents (EP 705245, EP 178041 and WO 95 / 00480). The oxidation can be acc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/16C07C57/46C07D211/22
CPCC07D211/22C07C51/16C07C57/46
Inventor M·K·沙尔马C·H·坎杜拉伊N·库马
Owner RANBAXY LAB LTD
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