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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: 2015-12-30
ZHEJIANG HUAHAI PHARMA CO LTD
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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
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preparation example
[0019] The first step: add 200ml of toluene, 45g of biphenyl bromide, 30g of imidazole aldehyde, and 0.5g of tetrabutylammonium bromide in sequence; add sodium hydroxide aqueous solution to react at room temperature until the raw materials have reacted completely, layer and wash. The organic layer is reduced by adding a reducing agent, crystallized by adding water, filtered, and dried to obtain the compound represented by formula 1.
[0020] Step 2: Add 150ml of toluene in sequence; add 43g of the compound shown in formula 1, catalyst, 30g of sodium azide, the reaction, the reaction is over, the product is extracted with sodium hydroxide aqueous solution, sodium nitrite, ethyl acetate are added dropwise hydrochloric acid to pH To 3-5, filter and wash the filter cake with water to obtain crude losartan to be refined (purity 95%-98%).
Embodiment 1
[0022] Add 50g of the crude losartan obtained by the above route into a 250ml three-necked flask, add 150ml of methanol; then heat to 60°C, stir for 1 hour, cool to 3°C, stir and crystallize for 2 hours, filter, and dry to obtain high purity Losartan , The yield is 90%, the purity is 99.4%, and the single impurities are 0.2%.
Embodiment 2
[0024] Add 50g of the crude losartan obtained by the above route into a 250ml three-necked flask, add 150ml of acetone; then heat to 60°C, stir for 1 hour, cool to 3°C, stir and crystallize for 2 hours, filter and dry to obtain high purity Losartan , The yield is 94%, the purity is 99.5%, and the single impurities are 0.15%.
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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 present invention relates to the field of medicine and chemical industry, in particular to a method for preparing high-purity losartan. technical background [0002] Losartan Potassium (Losartan Potassium) is an orally effective specific angiotensin II (AT1) receptor lift antagonist for the treatment of hypertension. Losartan is its free state or intermediate in the previous step, its chemical name is {2-butyl-4-chloro-1-[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl -1H-imidazol-5-yl}methanol. Losartan potassium can be obtained by reacting with potassium hydroxide and other potassium-containing salts or alkalis. [0003] With high-purity losartan, it is easier to obtain losartan potassium of better quality. Losartan is affected by the reaction conditions during the synthesis process, and it is easy to produce impurities such as polymers in the reaction process and solution state. The subsequent purification can achieve Losartan with 97% purity. To obtain...
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