Preparation method of pinoxaden

A technology of pinoxaden and nitrite, which is applied in the field of pinoxaden preparation, can solve the problems of not being environmentally friendly, expensive hydrobromic acid, and expensive Boc anhydride, and achieves low cost and high atom economy Effect

Active Publication Date: 2019-12-03
JIANGSU FLAG CHEM IND
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0014] The disadvantage of the existing synthetic method of compound 4 is that it uses Boc to protect hydrazine, Boc anhydride is expensive, the strategy of protecting group is poor in atom economy, not green and environmentally friendly, and finally it needs to use hydrobromic acid to deprotect the group, and hydrobromic acid is expensive

Method used

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  • Preparation method of pinoxaden
  • Preparation method of pinoxaden
  • Preparation method of pinoxaden

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] Step 1: Add 200 grams of acetonitrile, 53.5 grams of anhydrous copper chloride (0.4mol), 445.3 grams of 1,1-dichloroethylene (4.6mol) and 47.4 grams of tert-butyl nitrite in a 1-liter four-necked bottle (0.46mol), the reaction system was cooled to 10 degrees, and 50 grams of raw material 4-methyl-2,6-diethylaniline (0.3mol) was slowly added dropwise. After the addition was complete, the reaction was stirred at room temperature for 16 hours. The reaction system was suction-filtered to remove copper salts, and the filter cake was washed with 200 g of ethyl acetate. The filtrate was washed once with 100 grams of 10% hydrochloric acid, and then washed once with 80 grams of water. The organic phase was evaporated to dryness under normal pressure to obtain a crude product, which was slurried with 48 g of n-hexane to obtain 73.5 g of off-white solid 1, with a yield of 85.8%. 1 HNMR (CDCl 3 ) δppm: 1.19 (t, 6H), 2.30 (s, 3H), 2.62 (q, 4H), 3.85 (s, 2H), 6.93 (s, 2H).

[004...

Embodiment 2

[0049] Step 1: In a 1-liter four-neck flask, add 180 grams of acetonitrile, 48.2 grams of anhydrous copper chloride (0.36mol), 290.4 grams of 1,1-dichloroethylene (3mol) and 37.1 grams of tert-butyl nitrite ( 0.36mol), the reaction system was cooled to 10 degrees, and 50 grams of raw material 4-methyl-2,6-diethylaniline (0.3mol) was slowly added dropwise. After the addition was complete, the reaction was stirred at room temperature for 16 hours. The reaction system was suction-filtered to remove copper salts, and the filter cake was washed with 150 g of ethyl acetate. The filtrate was washed once with 100 grams of 10% hydrochloric acid, and then washed once with 80 grams of water. The organic phase was evaporated to dryness under normal pressure to obtain a crude product, which was slurried with 50 g of n-hexane to obtain 72.9 g of off-white solid 1, with a yield of 85.1%.

[0050] Step 2: Synthesis of 2,6-diethyl-4-methylphenylacetate: In a 1-liter four-neck flask, add 160 ...

Embodiment 3

[0056] Step 1: In a 2-liter four-necked flask, add 250 grams of acetonitrile, 51.8 grams of anhydrous cuprous chloride (0.52mol), 580.8 grams of 1,1-dichloroethylene (4.6mol) and 55.6 grams of tert-butyl nitrite ester (0.54mol), the temperature of the reaction system was lowered to 10°C, and 50 g of raw material 4-methyl-2,6-diethylaniline (0.3mol) was slowly added dropwise. After the addition was complete, the reaction was stirred at room temperature for 16 hours. The reaction system was suction-filtered to remove copper salts, and the filter cake was washed with 200 g of ethyl acetate. The filtrate was washed once with 100 grams of 10% hydrochloric acid, and then washed once with 90 grams of water. The organic phase was evaporated to dryness under normal pressure to obtain a crude product, which was slurried with 48 g of n-hexane to obtain 74.6 g of off-white solid 1, with a yield of 87.1%.

[0057] Step 2: Synthesis of 2,6-diethyl-4-methylphenylacetate: In a 2-liter four-...

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Abstract

The invention relates to the field of organic synthesis, in particular to a synthesis method of pinoxaden. The synthesis method comprises the following steps that under catalysis of copper chloride orcuprous chloride, 4-methyl-2,6-diethyl aniline reacts with 1,1-dichloroethylene and nitrous acid ester to generate a compound 1; the compound 1 reacts with sodium alcoholate, and a reaction product is subjected to acidic hydrolysis to obtain a compound 2; the compound 2 reacts with diester carbonate and strong base to obtain an intermediate 3; after diethylene glycol dimethanesulfonate reacts with hydrazine hydrate, salifying with hydrochloric acid is conducted to obtain an intermediate 4; the intermediate 3 and the intermediate 4 are subjected to ring forming under the effect of base to obtain a compound 5; and the compound 5 and pivaloyl chloride react under the effect of the base or base / DMAP to obtain the pinoxaden. The synthesis method of the pinoxaden does not use expensive or toxiccatalysts, does not need to adopt a protection / deprotection strategy, and has the characteristics of low cost and high atomic economy.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a preparation method of pinoxaden. Background technique [0002] Pinoxaden is a new phenylpyrazoline herbicide, and its mechanism of action is an acetyl-CoA carboxylase (ACC) inhibitor. It causes fatty acid synthesis to be blocked, cell growth and division to stop, cell membrane lipid-containing structure to be destroyed, and weeds to die. It has systemic conductivity and is mainly used to control annual grass weeds in barley fields. The results of indoor activity tests and field efficacy tests show that it has a good effect on annual grass weeds in barley fields such as wild oats, foxtails, barnyard grass, etc. Effectiveness. [0003] The existing method for synthesizing pinoxaden mainly involves synthesizing two key intermediates of compound 3 and compound 4 respectively, and then combining them; [0004] For compound 3, there are two existing synthetic methods: [0005] Ro...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D498/04
CPCC07D498/04
Inventor 卜龙张璞钱梓伟侯远昌王凤云
Owner JIANGSU FLAG CHEM IND
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