New preparation method of insect repellent albendazole

A technology of albendazole and a new method, which is applied in the field of preparation of albendazole, can solve the problems that the quality is difficult to reach the advanced standard, the crude product of albendazole has low purity, and the content of individual impurities is high, and the new synthetic process is simple High efficiency, easy separation and purification, and low impurity content

Active Publication Date: 2013-06-26
CHANGZHOU YABANG QH PHARMACHEM +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the lack of separation in the middle, the crude product of albendazole synthesized has low purity and deep color. Although the product purity can reach more than 98% after repeated refining, the produc

Method used

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  • New preparation method of insect repellent albendazole
  • New preparation method of insect repellent albendazole
  • New preparation method of insect repellent albendazole

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] Step 1 Preparation of 2,4-dichloronitrobenzene

[0037] In a 500ml four-neck flask equipped with a thermometer and a stirring device, start stirring, add 100.0g m-dichlorobenzene, 0.9 times the weight ratio of concentrated sulfuric acid, and the molar amount is 1.1 times m-dichlorobenzene nitric acid, and keep warm at 5-10°C After 3 hours, HPLC traced the reaction to be complete. The lower waste acid layer was separated, and 100 g of 5% sodium hydroxide aqueous solution was added to stir and wash. The lower layer was separated to obtain 125.0 g of 2,4-dichloronitrobenzene, which was directly used in the next reaction. This step yield is 95.7%, and content is 98.7%.

[0038] The preparation of step 2 2-nitro-5-chloroaniline

[0039] In a 1000ml autoclave, add 100.0g of 2,4-dichloronitrobenzene obtained in the previous step, methanol with a weight ratio of 3.5 times 2,4-dichloronitrobenzene, and 10 times 2,4-dichloronitrobenzene Benzene molar amount of ammonia water, th...

Embodiment 2

[0048] Step 12, the preparation of 4-dichloronitrobenzene

[0049] In a 500ml four-necked flask with a thermometer and a stirring device, start stirring, add 100.0g m-dichlorobenzene, 0.5 times the weight ratio of concentrated sulfuric acid, drop nitric acid in a molar amount that is 1.05 times m-dichlorobenzene, and control the dropping temperature at 10-15°C, after the dropwise addition is completed, keep the temperature at 10-15°C for 3 hours, follow the reaction by HPLC, remove the lower waste acid layer, add 100g of 15% sodium carbonate aqueous solution, stir and wash, and separate the lower layer to obtain 2,4- Dichloronitrobenzene 127.0g was directly used in the next step reaction. This step yield is 97.2%, and content is 98.1%.

[0050] The preparation of step 2 2-nitro-5-chloroaniline

[0051] Add 250.0g of 2,4-dichloronitrobenzene obtained in the previous step into a 1000ml autoclave, 2.5 times the weight ratio of 2,4-dichloronitrobenzene toluene, 12 times the weig...

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Abstract

The invention discloses a new preparation method of an insect repellent albendazole and provides a brand-new synthesis route of albendazole. The new preparation method adopting m-dichlorobenzene as the starting material is used for obtaining high-purity albendazole through nitration, amination, condensation, reduction and cyclization reaction; the new preparation method is characterized in that an unstable intermediate condensation compound 2-nitryl-4-propyl sulfenyl aniline in the existing industrial route is changed into 2-nitryl-5-propyl sulfenyl aniline with stable quality. The reducing process is changed into a clean and efficient reducing process by virtue of sodium sulfide. The synthesis process is simple and efficient, less in pollution, high in quality and suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of chemistry or medicinal chemistry, and in particular relates to a preparation method of albendazole. Background technique [0002] Albendazole (Albendazole) also known as albendazole, chemical name 5-propylthio-1H-benzimidazole-2-methyl carbamate, is a broad-spectrum high-efficiency and low-toxic anthelmintic drug, developed by the American Smith Kline was first listed on the market in 1977. At present, the drug is widely used in the clinical treatment of various helminth infectious diseases. It has a strong killing effect on nematodes, trematodes, and tapeworms parasitic on humans and animals. It is effective on human cysticercosis and intestinal nematodes. The effective rate of the disease is as high as 100%, and it can significantly inhibit the development of eggs, and has no accumulation in the body. [0003] Since the mid-70s, there have been many reports on the synthetic route of albendazole at home and abroa...

Claims

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Application Information

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IPC IPC(8): C07D235/32
Inventor 王学成朱建民苏文杰吴建才琚泽沁朱伟
Owner CHANGZHOU YABANG QH PHARMACHEM
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