Preparation method of benzbromarone
A technology of benzbromarone and ethylbenzene, applied in the field of chemical synthesis, can solve the problems of strong bromine corrosion, incomplete reaction, low reaction temperature, etc., and achieves improved reaction conditions, improved purification methods, and strong corrosiveness. Effect
Active Publication Date: 2012-09-12
NORTHEAST PHARMA GRP
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The synthetic method of benzbromarone reported in the literature is as follows: (1) the first step Friedel-Crafts acylation reaction, using the highly toxic solvent carbon disulfide as the reaction solvent; (2) the second step using a large excess of pyridine hydrochloride to carry out demethylation (3) The third step uses bromine to carry out bromination reaction, wherein bromine is highly corrosive, harmful to human body, and pollutes surroundings
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Embodiment 1
[0020] In a 1000mL reaction flask equipped with mechanical stirring, add 60g of 2-ethylbenzofuran, 75g of p-methoxybenzoyl chloride, and 500mL of dichloromethane. Add tin 110g, drop it in about 40 minutes, the color of the reaction solution turns red, and a brown-red solid gradually appears, keep the temperature at 0±3°C and continue stirring for 3 hours. After the reaction is over, slowly add 200 mL of ice water and 125 mL of aqueous hydrochloric acid (52.5 mL of concentrated hydrochloric acid) under stirring at 0°C to adjust the pH of the reaction solution to 1-2, then add 200 mL of dichloromethane for extraction, wash with water, Alkali washing, salt washing, anhydrous magnesium sulfate drying. After suction filtration and concentration, 110 g of yellow oil was obtained, with a yield of 95.8%.
Embodiment 2
[0016] Figure 5 It is the structural formula diagram of 2-ethyl-3-p-hydroxybenzoyl-benzofuran of the present invention.
Embodiment 3
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The invention relates to a preparation method of benzbromarone applied to the field of pharmaceutical synthesis, which comprises the following steps: taking 2-ethylbenzofuran and p-anisoyl chloride as starting raw materials, carrying out friedel-crafts acylation under the participation action of a catalyst and prepare 2-ethyl-3-p-methoxyphenyl formyl-benzofuran; carrying out demethylation reaction on the obtained 2-ethyl-3-p-methoxyphenyl formyl-benzofuran and pyridine hydrochloride, removing moisture in a reaction system by using a method that water is contained in toluene and preparing 2-ethyl-3-p-hydroxybenzene formyl-benzofuran; carrying out bromination reaction on the prepared 2-ethyl-3-p-hydroxybenzene formyl-benzofuran and bromide to prepare benzbromarone; and carrying out acidolysis with hydrochloric acid after the 2-ethylbenzofuran is fully reacted with the p-anisoyl chloride and extracting to obtain the 2-ethyl-3-p-methoxyphenyl formyl-benzofuran. The preparation method has the advantages that in the friedel-crafts acylation, methylene dichloride, trichloromethane and other halohydrocarbon are used for replacing carbon disulfide, and the post-processing process is simplified; and in the bromination reaction, bromine which is strong in corrosivity, generates great harm to human bodies and pollutes the environment is changed into the bromide.
Description
technical field [0001] The invention relates to a preparation method of benzbromarone in the field of chemical synthesis Background technique [0002] Benzbromarone (Benzbromarone), trade name tongfenglixian, chemical name ((3,5-dibromo-4-hydroxyphenyl)-(2-ethyl-3-benzofuranyl)methanone), Its structure is shown in formula (I), which is a novel uric acid excretion accelerator, which can improve diseases caused by excessive uric acid in the blood, such as gout and hypertension accompanied by hyperuricemia. The synthetic method of benzbromarone reported in the literature is as follows: (1) the first step Friedel-Crafts acylation reaction, using the highly toxic solvent carbon disulfide as the reaction solvent; (2) the second step using a large excess of pyridine hydrochloride to carry out demethylation (3) The third step uses bromine to carry out bromination reaction, wherein bromine is highly corrosive, harmful to human body, and pollutes surroundings. Therefore, researchin...
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IPC IPC(8): C07D307/80
Inventor 黄丽荣胡铁军李想白跃飞宋海生
Owner NORTHEAST PHARMA GRP
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