Method for synthesizing herbicide pyriminobac-methyl in paddy field

A synthesis method and a technology for pyrimifen, applied in the field of synthesizing the paddy field herbicide pyrimifen, can solve the problems of difficult industrialized production, unfavorable industrialized production, low reaction yield and the like, and achieve easy industrialized production and low production cost. , The effect of simple process operation

Pending Publication Date: 2021-02-23
CHANGZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] There are two traditional synthesis processes of pyrifluran. One key step uses the high-risk reagent n-butyllithium, which requires high operation and is difficult for industrial product...

Method used

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  • Method for synthesizing herbicide pyriminobac-methyl in paddy field
  • Method for synthesizing herbicide pyriminobac-methyl in paddy field
  • Method for synthesizing herbicide pyriminobac-methyl in paddy field

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] a. Preparation of 3-hydroxyphthalic anhydride

[0045] Add 3-chlorophthalic anhydride (22 grams, 120.5mmol), N,N-dimethylformamide (60mL), water (30mL) and catalyst cuprous chloride (2.38 grams, 24mmol) in the reaction flask, stir , add potassium hydroxide (27.04 g, 482 mmol), and react at 115°C for 12 hours. After the reaction, filter with suction, wash the filter cake with dichloromethane, adjust the pH value of the filtrate to 1~2, extract with dichloromethane, and collect the organic solvent And concentrated to obtain 22.1 grams of reddish-brown oily liquid 3-hydroxyphthalic acid, HPLC: 88%;

[0046] Add the above-mentioned 3-hydroxyphthalic acid (22.1 grams, HPLC: 88%) in the reaction flask, add acetic anhydride (36.8 grams, 361.5mmol), stir and heat to 80 ° C for 2 hours, after the reaction, the reaction solution decreases Concentrate under reduced pressure to obtain 18.2 g of reddish-brown oily liquid 3-hydroxyphthalic anhydride, with a yield of 80.1%.

[0047]...

Embodiment 2

[0064] a. Preparation of 3-hydroxyphthalic anhydride

[0065] Add 3-chlorophthalic anhydride (22 grams, 120.5mmol), N,N-dimethylformamide (60mL), water (30mL) and catalyst cuprous chloride (2.38 grams, 24mmol) in the reaction flask, stir , add potassium hydroxide (40.5 g, 723 mmol), and react at 105°C for 12 hours. After the reaction, filter with suction, wash the filter cake with dichloromethane, adjust the pH value of the filtrate to 1~2, extract with dichloromethane, and collect the organic solvent And concentrated to obtain 24.1 grams of reddish-brown oily liquid 3-hydroxyphthalic acid, HPLC: 86.7%;

[0066] Add the above-mentioned 3-hydroxyphthalic acid (24.1 g, HPLC: 86.7%) in the reaction flask, add acetic anhydride (27.04 g, 482 mmol), stir and heat to 70 ° C for 2 hours, after the reaction, the reaction solution is depressurized Concentrate to obtain 16.1 g of yellow oily liquid 3-hydroxyphthalic anhydride, with a yield of 70.7%.

[0067] H Spectrum: 1 H NMR(500MHz...

Embodiment 3

[0084] a. Preparation of 3-hydroxyphthalic anhydride

[0085] Add 3-chlorophthalic anhydride (22 grams, 120.5mmol), N,N-dimethylformamide (60mL), water (30mL) and catalyst cuprous bromide (4.18 grams, 24mmol) in the reaction flask, stirring , add potassium hydroxide (27.04 g, 482 mmol), and react at 110°C for 12 hours. After the reaction, filter with suction, wash the filter cake with dichloromethane, adjust the pH value of the filtrate to 1~2, extract with dichloromethane, and collect the organic solvent And concentrated to obtain 22.01 grams of reddish-brown oily liquid 3-hydroxyphthalic acid, HPLC: 81.9%;

[0086] Add the above-mentioned 3-hydroxyphthalic acid (22.01 grams, HPLC: 81.9%) in the reaction flask, add acetic anhydride (36.8 grams, 361.5 mmol), stir and heat to 80 ° C for 2 hours, after the reaction, the reaction solution decreases Concentrate under reduced pressure to obtain 15.1 g of reddish-brown oily liquid 3-hydroxyphthalic anhydride, with a yield of 62.9%....

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Abstract

The invention belongs to the field of fine chemical engineering, and particularly relates to a preparation method of herbicide pyriminobac-methyl for a paddy fields. The preparation method comprises the following steps: synthesizing 3-hydroxy phthalic anhydride by using 3-chlorophthalic anhydride as a new raw material, protecting carbonyl by using diethyl malonate, hydrolyzing to obtain 2-acetyl-6-hydroxy benzoic acid, and esterifying to obtain 2-acetyl-6-hydroxy methyl benzoate; then carrying out imidization reaction with methoxyamine hydrochloride to obtain 2-hydroxy-6-(1-methoxy iminoethyl-methyl)-benzoate, and finally, condensing with 2-tosyl-4, 6-dimethoxypyrimidine to obtain pyriminobac-methyl. In the process of preparing pyriminobac-methyl, high-risk reagents such as n-butyllithiumare avoided, a large amount of wastewater generated by diazotization is avoided, the income is increased, and the environment is protected.

Description

technical field [0001] The invention belongs to the field of fine chemicals, and in particular relates to a method for synthesizing the paddy field herbicide pyriflufen. Background technique [0002] Pyrimifluoride belongs to pyrimidine salicylic acid herbicides, which inhibit the growth of acetolactate synthase, so as to achieve the purpose of killing weeds. It is mainly used to control weeds in paddy fields. Field barnyardgrass has specific high activity, low usage, high safety and long service life for direct-seeding rice and transplanted rice. Pyriflufen is safe for the environment and humans and animals, and is suitable for large-scale use. [0003] There are two traditional synthesis processes of pyrifluran. One key step uses the high-risk reagent n-butyllithium, which requires high operation and is difficult for industrial production. The other key reaction is the diazotization reaction, which has a low yield and is A large amount of waste water is produced, which po...

Claims

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Application Information

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IPC IPC(8): C07D239/60
CPCC07D239/60
Inventor 徐德锋程松波胡航
Owner CHANGZHOU UNIV
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