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Preparation method of pinoxaden

A technology for pinoxaden and diazepine, which is applied in the field of preparation of technical compounds, can solve problems such as high cost and high environmental pressure, and achieve the effects of reducing the discharge of waste acid, reducing environmental pollution and improving safety

Inactive Publication Date: 2017-07-07
WUHAN INSTITUTE OF TECHNOLOGY
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] Although this synthetic patent method can achieve the purpose of synthesizing pinoxaden, it is difficult to prepare 2-(2,6-diethyl-4-methylbenzene) malonamide or 2-(2,6-diethyl The weak point that exists in the process of -4-methylbenzene) ethyl malonate is: (1) 2,6-diethyl-4-methylbromobenzene and malononitrile or diethyl malonate Used expensive bistriphenylphosphine palladium chloride as catalyst in the reaction process, the cost is too high for industrialized production; (2) 2-(2,6-diethyl-4-methylbenzene) malononitrile The preparation of 2-(2,6-diethyl-4-methylbenzene) malonamide by hydrolysis of concentrated sulfuric acid produces a large amount of sulfuric acid wastewater and the environment is under great pressure

Method used

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  • Preparation method of pinoxaden
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  • Preparation method of pinoxaden

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] To prepare pinoxaden, the specific steps are as follows:

[0041] 1. Synthesis of 4-methyl-2,6-diethylbromobenzene

[0042]

[0043] Add 65.2g (0.4mol) of 2,6-diethyl-4-methylaniline to 280g of hydrobromic acid solution with a mass fraction of 40%, cool to 0-5°C, and add sodium nitrite aqueous solution drop by drop (33.1g, 0.48mo1 sodium nitrite dissolved in 100mL water), after dripping, stir for 30min and then add 26.2g (0.2mo1) cuprous bromide, heat to 60°C for 4h, TCL tracking the reaction process, the reaction is over Finally, the mixture was poured into 250 mL of ice water, extracted three times with dichloromethane, then dried with anhydrous sodium sulfate and rotary evaporated, concentrated to obtain 92.36 g of crude product, and the fraction at 102-106 °C / 5 mmHg was collected by vacuum distillation to obtain 81.07 g product. Yield 89.2%.

[0044] 1 H NMR (CDCl 3 ) test data are: 1.22(t, 6H); 2.30(s, 3H); 2.85(m, 4H); 7.10(s, 2H).

[0045] 2. Synthesis o...

Embodiment 2

[0059] To prepare pinoxaden, the specific steps are as follows:

[0060] 1. The same method as in Example 1 was used to prepare 4-methyl-2,6-diethylbromobenzene.

[0061] 2. Synthesis of 2-(2,6-diethyl-4-methylbenzene)diethyl malonate

[0062]

[0063] Add 32.0g (0.2mol) of diethyl malonate, 16g (0.4mol) of sodium hydroxide and 100mL of N-methylpyrrolidone into a 250mL four-necked reaction flask equipped with a stirrer, a thermometer, and a condenser. Pass nitrogen protection, heat to 100-110°C, and react for 2 hours. Then add 22.7g (0.1mol) of 2,6-diethyl-4-methylbromobenzene and 1.2g of cuprous bromide, and react at 120-130°C for 10h. Cool, then remove the solvent under negative pressure -0.095MPa, 90°C, add 200g of water, adjust pH=3 with hydrochloric acid, extract with 3×80mL ethyl acetate, wash with 3×150mL water, concentrate, add 10mL n-hexane to freeze Crystallized, filtered, and washed with n-hexane to obtain 22.9 g of light yellow solid with a yield of 75%.

[...

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Abstract

The invention relates to a method for preparing pinoxaden. The steps are as follows: 2,6-diethyl-4-methylaniline undergoes a sandmeyer reaction to obtain 2,6-diethyl-4-methylbromobenzene, and then reacts with Malononitrile is coupled under the catalysis of copper iodide to obtain 2,6-bis-ethyl-4-methylphenylmalononitrile, and finally hydrolyzed in hydrogen peroxide solution to obtain 2,6-diethyl-4 -Methylphenylmalonamide; subsequent reaction with [1,4,5]-oxadiazepine dihydrobromide in the presence of triethylamine gives 8-(2,6-diethyl- 4-methylbenzene)tetrahydropyrazole[1,2d][1,4,5]-oxadiazepine-7,9-dione, preferably reacted with pivaloyl chloride to obtain pinoxaden ester. The present invention uses low-priced catalysts to reduce production costs. In addition, hydrogen peroxide-alkali is used as the hydrolysis system in the preparation process, which greatly reduces environmental pollution.

Description

technical field [0001] The invention belongs to the field of preparation of technical compounds, and in particular relates to a preparation method of pinoxaden. Background technique [0002] Pinoxaden chemical name: 8-(2,6-diethyl-4-methylphenyl)-l,2,4,5-tetrahydro-7-oxo-7H-pyrazol[1 ,2-d][1,4,5]Oxadiazepine-9-yl 2,2-dimethylpropionate, the chemical structure is: [0003] [0004] Pinoxaden is a new phenylpyrazoline herbicide developed by Syngenta Crop Protection Co., Ltd. in Switzerland. It is an acetyl-CoA carboxylase (ACC) inhibitor herbicide. The leaf absorbs it, and then conducts it to the meristem, causing fatty acid synthesis to be blocked, cell division to stop, cell membrane lipid-containing structure to be destroyed, and weeds to die. This variety is systemic and fast-acting. Generally, sensitive weeds stop growing within 48 hours after application, the weed leaves start to turn yellow within 1-2 weeks, and the weeds completely die within 3-4 weeks. The respo...

Claims

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Application Information

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IPC IPC(8): C07D498/04
CPCC07D498/04
Inventor 刘安昌董元海余玉郑怡倩汪焱鲁
Owner WUHAN INSTITUTE OF TECHNOLOGY
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