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A method for preparing high-purity losartan

A losartan, high-purity technology, applied in the field of preparation of high-purity losartan, can solve the problems of no practical production significance, no competitiveness, complicated process, etc., and achieve the effect of low cost, environmental friendliness and high refining yield

Active Publication Date: 2020-10-02
ZHEJIANG HUAHAI PHARMA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

To obtain losartan with a purity greater than 99%, it is reported in the literature that after losartan is prepared to obtain losartan potassium, losartan is obtained by dissociation with acid. Although the quality of losartan can be improved equally, the process is complicated and loss Larger, not competitive, and of no practical production significance

Method used

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  • A method for preparing high-purity losartan
  • A method for preparing high-purity losartan

Examples

Experimental program
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preparation example

[0020] Step 1: Add 200ml of toluene, 45g of biphenyl bromide, 30g of imidazole aldehyde, and 0.5g of tetrabutylammonium bromide in sequence; add aqueous sodium hydroxide solution and react at room temperature until the raw materials are completely reacted, separate layers, and wash. The organic layer was reduced by adding a reducing agent, crystallized by adding water, filtered, and dried to obtain the compound shown in Formula 1.

[0021] The second step: add 150ml of toluene in turn; put in 43g of the compound shown in formula 1, catalyst, 30g of sodium azide, react, the reaction is completed, extract the product with aqueous sodium hydroxide solution, add sodium nitrite, ethyl acetate and drop hydrochloric acid to pH To 3-5, filter, and wash the filter cake with water to obtain the crude losartan to be refined (purity 95%-98%).

Embodiment 1

[0023] Add 50 g of crude losartan obtained by the above route into a 250 ml three-necked flask, add 150 ml of methanol; then raise the temperature to 60°C, stir for 1 hour, cool down to 3°C, stir and crystallize for 2 hours, filter, and dry to obtain high-purity chlorine Sartan, yield 90%, purity 99.4%, simple impurity 0.2%.

Embodiment 2

[0025] Add 50 g of crude losartan obtained by the above route into a 250 ml three-necked flask, add 150 ml of acetone; then raise the temperature to 60°C, stir for 1 hour, cool down to 3°C, stir and crystallize for 2 hours, filter, and dry to obtain high-purity Losartan, 94% yield, 99.5% purity, 0.15% simple.

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Abstract

The invention relates to a method for preparing high-purity losartan. The method comprises steps as follows: (1), a losartan crude product is added to an organic solvent or a mixed solvent of an organic solvent and water, and the mixture is heated to reach 20-80 DEG C and stirred; (2), the system is cooled directly or cooled after water is added or cooled to 0-5 DEG C after a part of solvent is evaporated, a material is precipitated, filtered and dried, and losartan is obtained, wherein the organic solvent used in the step (1) is any one of tetrahydrofuran, butanone, acetone and methyl alcohol or is a mixed solvent of any one of the four solvents and water. The losartan obtained with the method has high purity, any individual impurity can be reduced to 0.2% or even under 0.1%, the purity of the losartan can reach 99.5%, the cost of the method is lower, the refining yield is high, and the method is very simple in operation, environment-friendly and suitable for industrial production.

Description

technical field [0001] The invention relates to the field of medicine and chemical industry, in particular to a method for preparing high-purity losartan. [0002] technical background [0003] Losartan potassium (Losartan Potassium) is an orally effective specific angiotensin II (AT1) receptor antagonist for the treatment of hypertension. Losartan is its free state or the intermediate of the previous step, its chemical name is {2-butyl-4-chloro-1-[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl -1H-imidazol-5yl}methanol. It reacts with potassium hydroxide and other potassium-containing salts or alkalis to obtain losartan potassium. [0004] With high-purity losartan, it is easier to obtain better quality losartan potassium. Losartan is affected by the reaction conditions during the synthesis process, and impurities such as polymers are easily produced during the reaction process and in the solution state. Subsequent refining can reach Losartan with a purity of 97%. And to obta...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D403/10
CPCC07D403/10
Inventor 张霭文董鹏王松青关启俊
Owner ZHEJIANG HUAHAI PHARMA CO LTD