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Preparation method of mequindox

A technology of acemetquine and benzofurazan, which is applied in the field of preparation of acemetquine, can solve the problems of waste of raw materials, lower product quality, and easy generation of impurities, so as to improve yield and product quality, reduce material and financial resources, Effect of reducing water content

Inactive Publication Date: 2012-11-28
HUBEI ZHONGMU ANDA PHARMACEUTICAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0013] 1. In the prior art, after benzofuran is synthesized from o-nitroaniline, steps such as separation, storage, drying, transshipment, and feeding are required. The intermediate process will cause waste of benzofuran and require additional manpower and material resources and financial resources, increased production costs
[0014] 2. Benzofurazan has a low melting point and is not easy to dry, which will cause about 10% of water in it, and the existence of water will affect the degree of the reaction of the synthesis of acemethaquine, reducing the yield of the synthesis of acemethaquine
At the same time, the variable amount of moisture contained in benzofurazan makes it difficult to accurately estimate the amount of feed, which is likely to cause waste of raw materials and affect production costs.
[0015] 3. Benzofurazan is unstable to heat, and impurities are easily produced during the drying process, which increases the side reactions in the condensation reaction process and reduces the quality of the product

Method used

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  • Preparation method of mequindox

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] Add 54g of o-nitroaniline, 18g of lye (30%), and 320g of sodium hypochlorite (10% to 15% of available chlorine) into a 500ml three-necked flask, and keep it warm for 10 hours at a temperature of 15°C, then add 80ml of xylene, Stir for 10 minutes to completely dissolve the benzofurazan produced by the reaction, transfer it to a 500ml separating funnel and let it stand for 15 minutes, remove the lower water layer and mechanical impurities, transfer the remaining organic layer into a 250ml three-neck flask, add 0.8g potassium hydroxide , the temperature was raised to 25°C, 38.5 g of acetylacetone was added dropwise, and after the addition was completed, the reaction was incubated for 6 hours, centrifuged, washed, and dried to obtain 65.8 g of acetylmethaquine, with a yield of 77.13%.

Embodiment 2

[0041] Add 54g of o-nitroaniline, 18g of lye (30%), and 320g of sodium hypochlorite (10% to 15% of available chlorine) into a 500ml three-necked flask, and keep it warm for 10 hours at a temperature of 20°C, then add 100ml of toluene and stir The benzofurazan produced by the reaction was completely dissolved in 10 minutes, transferred to a 500ml separatory funnel and left to stand for 15 minutes, the water layer and mechanical impurities below were separated, the remaining organic layer was transferred to a 250ml three-necked flask, 2.7g of ethanolamine was added, and the temperature was raised to At 30°C, 38.5 g of acetylacetone was added dropwise. After the addition, the mixture was incubated for 10 hours, then lowered to room temperature, centrifuged, washed, and dried to obtain 67.1 g of methylquine, with a yield of 78.65%.

Embodiment 3

[0043] Add 54g of o-nitroaniline, 18g of lye (30%), and 320g of sodium hypochlorite (10% to 15% of available chlorine) into a 500ml three-neck flask, and keep it warm for 6.5 hours at a temperature of 20°C, then add 200ml of toluene and stir For 10 minutes, transfer to a 500ml separating funnel and let it stand for 15 minutes to separate the lower water layer and mechanical impurities. Transfer the remaining organic layer to a 250ml three-neck flask, add 2g of diethylamine, heat up to 65°C, and dropwise add 38.5g of acetylacetone After the addition, the reaction was incubated for 6 hours, then cooled to room temperature, centrifuged, washed, and dried to obtain 68.3 g of methquine, with a yield of 80.06%.

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Abstract

The invention discloses a preparation method of mequindox, belonging to the field of medicine chemical industry. The preparation method comprises the following steps: carrying out redox reaction on o-nitroaniline and a sodium hypochlorite solution under alkaline conditions to obtain benzofurazan, and after the reaction finishes, and adding an organic solvent for extraction, thereby obtaining a benzofurazan organic solution; and adding a catalyst and acetylacetone into the benzofurazan organic solution to initiate condensation reaction, thereby obtaining the mequindox. The invention omits the steps of benzofurazan separation, storage, drying, transportation, addition, dissolution and the like, thereby saving the human resources, material resources and financial resources, reducing the loss of benzofurazan in the middle process, and lowering the production cost. Meanwhile, the invention separates water in the benzofurazan by extraction, thereby lowering the water content in the subsequent reaction and increasing the synthesis yield of mequindox.

Description

technical field [0001] The invention relates to a preparation method of acetylmethaquine, which belongs to the field of medicine and chemical industry. Background technique [0002] Acetylmethaquine (Shirella net), chemical name: 3-methyl-2-acetylquinoxaline-1,4-dioxide, belongs to broad-spectrum antibacterial drugs, and its effect on Gram-negative bacteria is stronger than that of Gram-positive bacteria , It has a strong effect on Treponema, and it is effective on piglet yellow scour, pullorum, calf diarrhea, paratyphoid fever, Pasteurella avian, chick pullorum, chicken Escherichia coli, and is mainly used for swine dysentery and bacterial enteritis caused by Treponema. [0003] The preparation method of Acetyl Mequin in the prior art is: [0004] (1) O-nitroaniline and sodium hypochlorite undergo oxidation-reduction reaction under alkaline conditions to obtain benzofurazan, which is centrifuged, washed with water, and dried to obtain solid benzofurazan. [0005] (2) Diss...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D241/52
Inventor 桂亮王峥袁碧娥程志鹏
Owner HUBEI ZHONGMU ANDA PHARMACEUTICAL CO LTD
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