Preparation method of fenbendazole intermediate 2-nitro-4-phenylthioaniline

A technology of phenylthioaniline and fenbendazole, which is applied in the field of preparation of fenbendazole intermediate 2-nitro-4-phenylthioaniline, can solve the problems of high cost, unfavorable industrialization and waste salt generation many problems, to achieve the effect of small waste water discharge, lower production cost and simple reaction process

Active Publication Date: 2020-06-30
SHANDONG GUOBANG PHARMA +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method produces a large amount of waste salt, and the cost is high, which is not conducive to industrialization

Method used

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  • Preparation method of fenbendazole intermediate 2-nitro-4-phenylthioaniline
  • Preparation method of fenbendazole intermediate 2-nitro-4-phenylthioaniline
  • Preparation method of fenbendazole intermediate 2-nitro-4-phenylthioaniline

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Add methanol 120g, o-nitroaniline 27.63g, and ammonium thiocyanate 15.99g in a 250ml four-necked bottle, stir evenly, feed chlorine gas to control the reaction temperature at 15°C, and filter to obtain a solid thiocyanation product ( 4-thiocyano-2nitroaniline) 36.88g, yield 94.45%.

[0032] Add 36.88g of thiocyanation product (4-thiocyano-2nitroaniline) to a 250ml four-necked flask, 100g of purified water, add 8.31g of sodium hydroxide, control the reaction temperature at 35°C, and filter after 20min of reaction An aqueous solution containing 35.59 g of sodium 4-amino-3-nitrobenzenethiophenate was obtained, with a yield of 98.12%;

[0033] 4-amino-3-nitrobenzene sodium aqueous solution is warmed up to 60 DEG C, drips the ethanol solution that contains 29.10g bromobenzene, adds extraction agent toluene (toluene according to its and 4-amino-3-nitrobenzene Sodium sulfur aqueous solution was added in a mass ratio of 1:1), and stirred for 10 min to obtain a toluene solution...

Embodiment 2

[0035] Add 120g of methanol, 27.63g of o-nitroaniline, and 15.99g of ammonium thiocyanate in a 250ml four-necked bottle, stir evenly, feed chlorine gas, control the reaction temperature at 18°C, and filter to obtain the thiocyanation product (4 -thiocyano-2 nitroaniline) 36.77g, yield 94.15%.

[0036] In a 250ml four-necked flask, add 36.77g of thiocyanation product (4-thiocyano-2nitroaniline), 100g of methanol, add 8.29g of sodium hydroxide, control the reaction temperature at 38°C, and filter after 20 minutes of reaction to obtain An alcohol solution containing 35.42 g of sodium 4-amino-3-nitrobenzenethiophenate, with a yield of 97.98%;

[0037] Raise the temperature of the 4-amino-3-nitrobenzenethiosodium alcohol solution to 62°C, add dropwise an ethanol solution containing 34.76g of bromobenzene, add water (according to its mass ratio to toluene at 1:1) and extract Agent toluene (toluene is added according to the ratio of 1:1 of its mass ratio with 4-amino-3-nitrophenylth...

Embodiment 3

[0039] Add 120g of methanol, 27.63g of o-nitroaniline, and 15.99g of ammonium thiocyanate in a 250ml four-necked bottle, stir evenly, feed chlorine, control the reaction temperature at 20°C, and filter to obtain the thiocyanation product (4 -thiocyano-2nitroaniline) 36.71g, yield 94.01%.

[0040] Add thiocyanation product (4-thiocyano-2 nitroaniline) 36.71g in 250ml four-necked bottle, 100g volume concentration is the ethanol of 60%, add sodium hydroxide 9.02g, control reaction temperature is 40 ℃, through After 20 minutes of reaction, an alcoholic solution containing 35.69 g of sodium 4-amino-3-nitrobenzenethiophenate was obtained by filtration, with a yield of 98.87%;

[0041] Raise the temperature of the 4-amino-3-nitrobenzenethiosodium alcohol solution to 65°C, add dropwise an ethanol solution containing 35.02g of bromobenzene, add water (according to its mass ratio to toluene at 1:1) and extract Agent toluene (toluene is added according to the ratio of 1:1 of its mass ra...

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Abstract

The invention relates to the technical field of veterinary drugs, and in particular, relates to a preparation method of fenbendazole intermediate 2-nitro-4-phenylthioaniline. The preparation method comprises the following steps: by taking o-nitroaniline and ammonium thiocyanate as raw materials and an organic solvent as a solvent of a reaction system, uniformly stirring and mixing, introducing chlorine, and filtering after the reaction of the raw materials is finished, so as to obtain 4-thiocyano-2-nitroaniline; taking 4-thiocyano-2-nitroaniline, adding sodium hydroxide and a reaction solvent,stirring and mixing, and filtering after the reaction is finished to obtain a sodium 4-amino-3-nitrothiophenol solution; carrying out a reaction on the sodium 4-amino-3-nitrothiophenol solution withbromobenzene under an alkaline condition, and after the reaction is finished, extracting to obtain the 2-nitro-4-phenylthioaniline. The preparation method is simple in process, the production cost isreduced, the production potential safety hazard can be reduced, the product yield is relatively high, and the environmental pollution is reduced.

Description

technical field [0001] The invention relates to the technical field of veterinary medicine, in particular to a preparation method of fenbendazole intermediate 2-nitro-4-phenylthioaniline. Background technique [0002] Fenbendazole is a broad-spectrum anthelmintic with high efficiency and low toxicity. It can drive and kill parasites such as roundworms, hookworms, whipworms, some tapeworms and strongyloids in the gastrointestinal tract of animals. It has the advantages of safety, low toxicity and good applicability. . By affecting the transport and energy metabolism of cells, it can prevent the aggregation of microtubules, destroy the integrity and energy transmission function of parasite cells, and finally achieve the effect of deworming. [0003] The prior art discloses a preparation method of fenbendazole, which includes (1) nitration reaction: using m-dichlorobenzene as a raw material, in concentrated sulfuric acid and nitric acid, undergoing nitration reaction, removing...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C331/12C07C319/14C07C319/02C07C323/37
CPCC07C319/02C07C319/14C07C331/12C07C323/37
Inventor 宋南廖仕学乔建超于童董真奇
Owner SHANDONG GUOBANG PHARMA
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