Method for preparing pendimethalin

A pendimethalin and dimethyl technology, which is applied in the preparation of amino compounds, chemical instruments and methods, and the preparation of organic compounds, can solve the problems of long routes and achieve simple equipment requirements, easy production, and reaction process routes short effect

Inactive Publication Date: 2013-06-12
SHANGHAI MARITIME UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The route of this production process is relatively long

Method used

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  • Method for preparing pendimethalin
  • Method for preparing pendimethalin

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Embodiment 1

[0022] Under nitrogen protection, 15 ml of anhydrous DMF, 3.72 g of m-bromo-o-xylene, 3.48 g of 3-pentylamine, 8.48 g of anhydrous potassium phosphate, 0.19 g of cuprous iodide and 0.76 g of N, N-diethyl salicylamide, the above reaction mixture was reacted at 80° C. for 24 hours under stirring. Cool to room temperature, add 30 ml of water, extract with ethyl acetate (15 ml x 2 times), separate the organic phase, distill off the solvent ethyl acetate, and the remaining 3.55 g of crude product is directly used for the next step of nitration reaction.

[0023] The operation method of nitration reaction mainly refers to patents IN 181756 and US5922913. The above 3.55 g of crude product and 6 g of acetic acid were mixed, heated to 60° C., a mixture of 3.2 g of concentrated nitric acid and 3.2 g of acetic acid was added dropwise with stirring, and stirring was continued at 60° C. for 2.5 hours. Cool to room temperature, dilute with 20 mL of water, and extract the product with 1,2-d...

Embodiment 2

[0025] Under nitrogen protection, 15 ml of anhydrous DMF, 3.72 g of m-bromo-o-xylene, 3.48 g of 3-pentylamine, 2.76 g of anhydrous potassium carbonate, 0.19 g of cuprous iodide and 0.76 g of N, N-diethyl salicylamide, the above reaction mixture was reacted at 90° C. for 24 hours under stirring. Cool to room temperature, add 30 ml of water, and extract with toluene (15 ml x 3 times). The organic phase was washed with 15 milliliters of 5% dilute hydrochloric acid, and the aqueous phase was adjusted to pH 8-9 with 30% sodium hydroxide solution, then extracted 2 times with toluene, and the solvent toluene was evaporated, and the remaining crude product (3.32 g) and 6 g Acetic acid was mixed, heated to 60°C, a mixture of 3.2 g of concentrated nitric acid and 3.2 g of acetic acid was added dropwise with stirring, and stirring was continued at 60°C for 2.5 hours. Cool to room temperature, dilute with 20 mL of water, and extract the product with 1,2-dichloroethane (10 mL×3). The lay...

Embodiment 3

[0027] Under nitrogen protection, 20 milliliters of anhydrous DMF, 3.72 grams of m-bromo-o-xylene, 3.48 grams of 3-pentylamine, 2.76 grams of anhydrous potassium carbonate, and 0.29 grams of cuprous oxide were successively added to a 100 milliliter autoclave, and the above reaction mixture was Under stirring, react at 120° C. for 24 hours. Cool to room temperature, add 30 ml of water, and extract with toluene (15 ml x 3 times). The organic phase was washed with 15 milliliters of 5% dilute hydrochloric acid, and the aqueous phase was adjusted to pH 8-9 with 30% sodium hydroxide solution, then extracted twice with ethyl acetate, the solvent ethyl acetate was evaporated, and the remaining crude product (2.96 g ) and acetic acid (6 g), heated to 60°C, a mixture of concentrated nitric acid (3.2 g) and acetic acid (3.2 g) was added dropwise with stirring, and stirring was continued at 60°C for 2.5 hours. Cool to room temperature, dilute with 20 mL of water, and extract the product ...

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Abstract

The invention provides a method for preparing pendimethalin. The method mainly comprises the following steps of: performing an amination on interhalogen o-xylene and 3-amylamine, which serve as initiative raw materials, in the presence of a catalyst and then performing a nitration reaction to prepare the pendimethalin. Compared with the prior art, the method has a short reaction process route; the pendimethalin yield is over 70 percent; the problem of nitration selectivity of o-xylene in the prior art is avoided; and the price of an adopted catalytic system is low.

Description

technical field [0001] The invention relates to a method for preparing pendimethalin. Background technique [0002] Pendimethalin (pendimethalin), the chemical name is N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitroaniline, other trade names include pendimethalin, Tianbu, Chuyatong, Chucaotong, Aminograss, Shacaotong, Caicaotong, etc. Pendimethalin is a high-efficiency, low-toxicity, environment-friendly, and easy-to-use pesticide. It has become the largest selective herbicide in the world. In recent years, it has a large demand at home and abroad and a broad market. [0003] At present, the production process (Scheme 1) of this pesticide is the reductive alkylation and nitration of m-nitro-o-xylene. Among them, the production technical problems of m-nitro-ortho-xylene have not been completely resolved, that is, the selectivity of the nitration reaction of ortho-xylene is not good, and the ratio of m-nitro-ortho-xylene to ortho isomers is equivalent, [Skupinski, W.; Milczak, T...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C211/52C07C209/76
Inventor 王军华周云张希琴
Owner SHANGHAI MARITIME UNIVERSITY
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