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Synthesis method of pyrazosulfuron-ethyl intermediate 4-ethoxycarbonyl-5-sulfamine-1-methylpyrazole

A technology of ethoxycarbonyl and methylpyrazole, applied in the field of organic synthesis, can solve the problems of many side reactions, low total yield, high production cost, etc., and achieve the effects of low environmental pollution, high total yield and high product purity

Active Publication Date: 2017-06-20
江苏省农用激素工程技术研究中心有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] The method has low total yield, many side reactions, high production cost, and is not suitable for industrialized production

Method used

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Experimental program
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Embodiment 1）

[0031] The synthetic method of the pyrazole sulfonamide of the present embodiment has the following steps:

[0032] ①Add 48.0g of sodium hydroxide (1.2mol), 400mL of DMSO and 102.0g of 4-ethoxycarbonyl-5-hydroxy-1-methylpyrazole (0.6mol) into the reaction device, ℃, the same below) stirred and reacted for 30 minutes, cooled to below 0 ℃, added 111.2 g of dimethylaminothioformyl chloride (0.9 mol), and reacted at about 5 ℃ for 4 hours.

[0033] After the reaction, add water to the reaction flask, stir for 10min, filter, wash with water, and dry to obtain 150.0g of the intermediate 4-ethoxycarbonyl-5-dimethylcarbamoyloxy-1-methylpyrrole Azole, the purity is 98.0%, and the yield is 97.3%.

[0034] ②Add 128.5g of intermediate 4-ethoxycarbonyl-5-dimethylaminothioformyloxy-1-methylpyrazole (0.5mol) and 200mL of n-dodecane to the reaction device, and heat up to Reflux, follow the gas phase until the reaction is complete (about 6h), then let it stand for separation, and recycle the ...

Embodiment 2）

[0039] The synthetic method of the pyrazole sulfonamide of the present embodiment has the following steps:

[0040] ①Add 120.0g of sodium hydroxide (3mol), 1000mL of DMSO and 255.0g of 4-ethoxycarbonyl-5-hydroxy-1-methylpyrazole (1.5mol) into the reaction device, stir at room temperature for 30min and then cool When the temperature is below 0°C, add 278.0g of dimethylaminothioformyl chloride (2.25mol) and react at about 5°C for 4 hours.

[0041] After the reaction, add water to the reaction flask, stir for 15min, filter, wash with water, and dry to obtain 370.0g of intermediate 4-ethoxycarbonyl-5-dimethylcarbamoyloxy-1-methylpyrrole Azole, the purity is 98.0%, and the yield is 96.0%.

[0042] ②Add 257.0g of intermediate 4-ethoxycarbonyl-5-dimethylaminothioformyloxy-1-methylpyrazole (1mol) and 400mL of n-dodecane to the reaction device, and heat up to reflux , followed by the gas phase until the reaction was complete (about 6h), then allowed to stand for stratification, and t...

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Abstract

The invention discloses a synthesis method of a pyrazosulfuron-ethyl intermediate 4-ethoxycarbonyl-5-sulfamine-1-methylpyrazole. The method comprises the following steps: (1) performing condensation reaction on 4-ethoxycarbonyl-5-hydroxyl-1-methylpyrazole and dimethylthiocarbamoyl chloride to obtain 4-ethoxycarbonyl-5-dimethylthio carbamoyl oxy-1-methylpyrazole; (2) performing transposition rearrangement reaction on the 4-ethoxycarbonyl-5-dimethylthio carbamoyl oxy-1-methylpyrazole to obtain 4-ethoxycarbonyl-5-dimethyl carbamoyl sulfenyl-1-methylpyrazole; (3) performing chlorosulfonation reaction on the 4-ethoxycarbonyl-5-dimethyl carbamoyl sulfenyl-1-methylpyrazole and chlorine to obtain 4-ethoxycarbonyl-5-sulfonyl chloride-1-methylpyrazole; (4) performing ammoniation reaction on the 4-ethoxycarbonyl-5-sulfonyl chloride-1-methylpyrazole and ammonium hydroxide to obtain the 4-ethoxycarbonyl-5-sulfamine-1-methylpyrazole. The method is less in environment pollution, particularly high in product purity, and high in total yield.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, in particular to a method for synthesizing pyrazosulfuron-methyl intermediate 4-ethoxycarbonyl-5-sulfonamido-1-methylpyrazole. Background technique [0002] 4-Ethoxycarbonyl-5-sulfonamido-1-methylpyrazole is an important intermediate for the preparation of pyrazosulfuron-methyl, a sulfonylurea herbicide. [0003] At present, the preparation method of 4-ethoxycarbonyl-5-sulfonamido-1-methylpyrazole mainly contains following two kinds: [0004] (1) Using 4-ethoxycarbonyl-5-amino-1-methylpyrazole as a raw material, it is obtained through diazotization reaction, sulfonation reaction, and ammoniation reaction in sequence (see Chinese patent document CN102603636A). [0005] The amount of three wastes in this method is huge, which cannot meet the needs of green production. [0006] (2) Using 4-ethoxycarbonyl-5-hydroxyl-1-methylpyrazole as raw material, it can be obtained through chlorination...

Claims

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Application Information

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IPC IPC(8): C07D231/18
CPCC07D231/18
Inventor 孙永辉张元元高建红孔繁蕾
Owner 江苏省农用激素工程技术研究中心有限公司
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