Synthesis method of antagonist medicine intermediate o-nitrobenzoic acid

A technology for the synthesis of nitrobenzoic acid and its synthesis method, which is applied in the field of synthesis of o-nitrobenzoic acid, an intermediate of antagonist drugs, can solve the problems of complex process and low final yield, reduce intermediate links, shorten reaction time, The effect of increasing the reaction yield

Inactive Publication Date: 2018-10-09
CHENGDU ZHONGHENG HUATIE TECH CO LTD
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

[0002] O-nitrobenzoic acid is mainly used in pharmaceutical synthesis and organic synthesis, and can be used for the synthesis of 5HT2-D2 antagonist drug intermediates. However, most of the existing synthetic methods use potassium permanganate as the reactant, and the process is more complicated. The yield is not very high, therefore, it is necessary to propose a new synthetic method, which has important economic significance for further improving the quality and yield of the product and reducing the content of by-products

Method used

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  • Synthesis method of antagonist medicine intermediate o-nitrobenzoic acid

Examples

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example 1

[0010] Add 3mol of 2-ethyl-3-nitrophenol into the reaction vessel, 4mol mass fraction of 75% ethylene glycol monopropyl ether solution, raise the temperature of the solution to 30°C, control the stirring speed at 150rpm, keep it for 30min, and then Add 6 mol of triphenylphosphine powder, continue to react for 60 minutes, reduce the solution temperature to 5°C, precipitate solids, filter, wash with 85% propionic anhydride solution in mass fraction, and 91% triethylamine solution in mass fraction, and then Recrystallize in a 2-methylpentane solution with a mass fraction of 90%, and dehydrate with a dehydrating agent to obtain 445.89 g of crystalline o-nitrobenzoic acid, with a yield of 89%.

example 2

[0012] Add 3 mol of 2-ethyl-3-nitrophenol and 4.5 mol of ethylene glycol monopropyl ether solution with a mass fraction of 78% in the reaction vessel, raise the temperature of the solution to 32° C., control the stirring speed at 160 rpm, and keep it for 40 min. Then add 6.5 mol of triphenylphosphine powder, continue to react for 70min, lower the solution temperature to 6°C, precipitate solid, filter, wash with propionic anhydride solution with mass fraction of 88%, and triethylamine solution with mass fraction of 92% Wash, then recrystallize in 2-methylpentane solution with a mass fraction of 93%, and dehydrate with a dehydrating agent to obtain 460.92 g of crystalline o-nitrobenzoic acid, with a yield of 92%.

example 3

[0014] Add 3mol of 2-ethyl-3-nitrophenol into the reaction vessel, 5mol mass fraction of 80% ethylene glycol monopropyl ether solution, increase the solution temperature to 35°C, control the stirring speed at 170rpm, keep it for 50min, and then Add 7 mol of triphenylphosphine powder, continue the reaction for 90 minutes, lower the solution temperature to 8°C, precipitate solids, filter, and wash successively with 90% propionic anhydride solution and 94% triethylamine solution, Then recrystallize in 2-methylpentane solution with a mass fraction of 95%, and dehydrate with a dehydrating agent to obtain 475.95 g of crystalline o-nitrobenzoic acid with a yield of 95%.

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Abstract

The invention provides a synthesis method of an antagonist medicine intermediate o-nitrobenzoic acid. The method mainly comprises the following steps of adding 3mol of 2-ethyl-3-nitrophenol and 4 to 5mol of ethylene glycol monopropyl ether solution into a reaction container; raising the solution temperature to 30 to 35 DEG C; controlling the stirring speed being 150 to 170 rpm; maintaining the state for 30 to 50min; then, adding 6 to 7mol of triphenylphosphine powder; continuously performing reaction for 60 to 90min; lowering the solution temperature to 5 to 8 DEG C; separating out solid; performing filtering; sequentially using propionic anhydride solution for washing and triethylamine solution for washing; then, performing recrystallization in the 2-methyl pentane solution; performing dewatering by a dewatering agent; obtaining crystal o-nitrobenzoic acid.

Description

technical field [0001] The invention relates to a method for synthesizing an antagonist medicine intermediate o-nitrobenzoic acid. Background technique [0002] O-nitrobenzoic acid is mainly used in pharmaceutical synthesis and organic synthesis, and can be used for the synthesis of 5HT2-D2 antagonist drug intermediates. However, most of the existing synthetic methods use potassium permanganate as the reactant, and the process is more complicated. The yield is not very high, therefore, it is necessary to propose a new synthetic method, which has important economic significance for further improving the quality and yield of the product and reducing the content of by-products. Contents of the invention [0003] The object of the present invention is to provide a kind of synthetic method of antagonist medicine intermediate o-nitrobenzoic acid, comprises the steps: [0004] (i) Add 3 mol of 2-ethyl-3-nitrophenol and 4-5 mol of ethylene glycol monopropyl ether solution in the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C201/12C07C205/57
CPCC07C201/12C07C205/57
Inventor 彭响亮
Owner CHENGDU ZHONGHENG HUATIE TECH CO LTD
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