阅读说明：本技术 一种k胺中间体2-(羟基亚氨基)-n-(2-甲基苯基)乙酰胺合成工艺 (Synthesis process of K amine intermediate 2- (hydroxyimino) -N- (2-methylphenyl) acetamide ) 是由 高维丹 王艳 徐婷 夏雪强 冯维春 于 2020-07-16 设计创作，主要内容包括：本发明公开了一种K胺中间体2-(羟基亚氨基)-N-(2-甲基苯基)乙酰胺合成新工艺。该工艺以邻氨基甲苯为主要起始原料,通过氨基乙酰化和肟化两步,实现2-(羟基亚氨基)-N-(2-甲基苯基)乙酰胺的合成。与现有工艺相比产品收率达到97％以上同时减少3倍以上废盐氯化钠和硫酸钠的产生,且中间原料价格低,工艺简单,成本下降,实现环境与经济效益双方面提高。(The invention discloses a novel synthesis process of a K amine intermediate 2- (hydroxyimino) -N- (2-methylphenyl) acetamide. The process takes o-aminotoluene as a main starting material, and realizes the synthesis of 2- (hydroxyimino) -N- (2-methylphenyl) acetamide through two steps of amino acetylation and oximation. Compared with the prior art, the product yield reaches more than 97%, the generation of waste salt sodium chloride and sodium sulfate is reduced by more than 3 times, the price of intermediate raw materials is low, the process is simple, the cost is reduced, and the improvement of the environmental and economic benefits is realized.)

1. A production process of a K amine intermediate 2- (hydroxyimino) -N- (2-methylphenyl) acetamide is characterized by comprising the following steps:

2. the process for producing the K amine intermediate 2- (hydroxyimino) -N- (2-methylphenyl) acetamide according to claim 1, comprising the following steps:

(1) adding raw materials of o-aminotoluene and a solvent into a reaction bottle, controlling the temperature to be 10-30 ℃, dropwise adding acetic anhydride into the reaction bottle, keeping the temperature for reaction for 1-2h after dropwise adding, filtering, and then drying in vacuum to obtain o-acetamido toluene;

(2) and (2) sequentially adding acetic acid serving as a solvent and the acetamido toluene obtained in the step (1) into a reaction bottle, controlling the temperature to be 10-30 ℃ in the whole process, dropwise adding an oximation reagent, continuing to react for 1-4h after the feeding is finished for 0.5-2 h, adding ice water after the reaction is finished, filtering, and drying in vacuum to obtain the 2- (hydroxyimino) -N- (2-methylphenyl) acetamide.

3. The process for producing 2- (hydroxyimino) -N- (2-methylphenyl) acetamide, a K-amine intermediate as claimed in claim 2 wherein the solvent in step (1) is selected from acetic acid, 1, 2-dichloroethane, DMF.

4. The process for producing a K amine intermediate 2- (hydroxyimino) -N- (2-methylphenyl) acetamide according to claim 2, wherein in the step (1), the ratio of the amount of acetic anhydride to the amount of o-aminotoluene is 1.0 to 1.5: 1.

5. the process for producing 2- (hydroxyimino) -N- (2-methylphenyl) acetamide, which is an intermediate of K-amine according to claim 2, wherein the oximation reagent in the step (2) is selected from any one of a combination of acid and sodium nitrite, ethyl nitrite, isopropyl nitrite, N-butyl nitrite, isoamyl nitrite and N-amyl nitrite.

6. The process for producing a K amine intermediate, 2- (hydroxyimino) -N- (2-methylphenyl) acetamide, according to claim 2 wherein the ratio of the amount of the oximation agent to the amount of the acetamido toluene in step (2) is 1.1 to 2.0.

7. The process for producing 2- (hydroxyimino) -N- (2-methylphenyl) acetamide, which is an intermediate of K-amine, according to claim 5, wherein the acid is a combination of an acid and sodium nitrite, and the acid is any one of hydrochloric acid, nitric acid and sulfuric acid.

8. The process for producing the K amine intermediate 2- (hydroxyimino) -N- (2-methylphenyl) acetamide according to claim 5 wherein the oximation agent is selected from the group consisting of acids and sodium nitrite in a mass ratio of 1: 1.

9. The process for producing a K-amine intermediate, 2- (hydroxyimino) -N- (2-methylphenyl) acetamide, according to claim 2 wherein the mass of ice water added in step (2) is 5 times the mass of the reaction solution.

Technical Field

The invention relates to the field of organic chemical engineering, in particular to a synthesis process of a K amine intermediate 2- (hydroxyimino) -N- (2-methylphenyl) acetamide.

Background

The problem of resistance of plant diseases and insect pests to pesticide varieties is always one of the problems faced by pesticide researchers, and the DuPont company in the United states discovered a novel pesticide o-formylaminobenzamide compound in 2000, which has been applied to a wider range due to its high insecticidal activity and high safety to mammals, and reached a sale rate of $ 13.6 billion in 2016, so that the research and development of o-formylaminobenzamide compounds are more and more concerned by pesticide companies and research and development units.

The K amine is used as an important raw material of chlorantraniliprole, and the traditional production process mainly comprises the following two steps:

process one

Process two

The first main oximation step of the process needs hydroxylamine and chloral hydrate, generates more than 4 times of waste salt, and uses hydroxylamine which is expensive and has poor economic and environmental benefits.

Process two involves the problems of nitration and high pressure hydrogenation. Because a plurality of active sites exist in the nitration, the selectivity of the nitration target product is lower than 40 percent, and the separation process of various nitration products is complex; meanwhile, high temperature and high pressure are involved in hydrogenation, and unsafe factors in the production process are increased.

In summary, the problems of complex process, serious pollution, more three wastes and the like exist in the prior K amine production process, and the development and application of chlorantraniliprole are restricted, so that the development and research of a new K amine production process becomes an urgent need.

Disclosure of Invention

The invention mainly solves the technical problems that a novel production process of a K amine intermediate 2- (hydroxyimino) -N- (2-methylphenyl) acetamide is provided aiming at a K amine production process, and the problems of more waste salt, complex process, high cost and the like in the K amine production process are solved.

A production process of a K amine intermediate 2- (hydroxyimino) -N- (2-methylphenyl) acetamide comprises the following steps:

the production process of the K amine intermediate 2- (hydroxyimino) -N- (2-methylphenyl) acetamide comprises the following specific steps:

(1) adding raw materials of o-aminotoluene and a solvent into a reaction bottle, controlling the temperature to be 10-30 ℃, dropwise adding acetic anhydride into the reaction bottle, keeping the temperature for reaction for 1-2h after dropwise adding, filtering, and then drying in vacuum to obtain o-acetamido toluene;

(2) and (2) sequentially adding acetic acid serving as a solvent and the acetamido toluene obtained in the step (1) into a reaction bottle, controlling the temperature to be 10-30 ℃ in the whole process, dropwise adding an oximation reagent, continuing to react for 1-4h after the feeding is finished for 0.5-2 h, adding ice water after the reaction is finished, filtering, and drying in vacuum to obtain the 2- (hydroxyimino) -N- (2-methylphenyl) acetamide.

The solvent in the step (1) is selected from acetic acid, 1, 2-dichloroethane and DMF;

in the step (1), the use amount ratio of acetic anhydride to o-aminotoluene is 1.0-1.5: 1;

the oximation reagent in the step (2) is selected from any one of a composition of acid and sodium nitrite, ethyl nitrite, isopropyl nitrite, n-butyl nitrite, isoamyl nitrite and n-amyl nitrite;

in the step (2), the dosage ratio of the oximation reagent to the acetamido toluene is 1.1-2.0;

the acid is a composition of acid and sodium nitrite, and the acid is any one of hydrochloric acid, nitric acid and sulfuric acid;

when the oximation reagent is selected from the composition of acid and sodium nitrite, the mass ratio of the acid to the sodium nitrite is 1: 1;

the mass of the ice water added in the step (2) is 5 times of that of the reaction liquid;

selecting acetic anhydride to amidate amino to form carbon-oxygen double bond, activating alpha position H of double bond and forming enol; the oximation reagent used in the step (2) mainly comprises sodium nitrite + acid and several kinds of nitrous acid esters, the acidified sodium nitrite or nitrous acid esters can release nitroso free radical molecules in the reaction process, the nitroso free radicals are combined with activated enol to generate unstable nitrosoketone, and oximation products, namely corresponding 2- (hydroxyimino) -N- (2-methylphenyl) acetamide, are obtained through rearrangement.

And 2) sequentially adding solvents acetic acid and acetamido toluene into a reaction bottle, adding a solid and then adding the solvent to form a mass easily, and adding the solvent and then adding the solid to disperse the solid in the solvent well.

The invention has the beneficial effects that a new process is developed aiming at the problems of large amount of waste salt, complex process, high cost and the like caused by using chloral hydrate, hydroxylamine hydrochloride and other raw materials in the traditional process for producing the K amine intermediate, o-aminotoluene is used as a raw material, acetic anhydride is selected to amidate amino, and then an oximation reagent is selected to oximate the alpha position of carbonyl to obtain the K amine intermediate 2- (hydroxyimino) -N- (2-methylphenyl) acetamide. The method avoids using expensive hydroxylamine hydrochloride and chloral, changes cheap and easily-obtained sodium nitrite + acid or nitrite ester as an oximation reagent, reduces the raw material cost and the waste salt generation amount, has low cost and high yield, is environment-friendly, and compounds a green chemistry concept.

Drawings

FIG. 1 shows nuclear magnetic H spectra of the K amine intermediate 2- (hydroxyimino) -N- (2-methylphenyl) acetamide prepared in example 1

Detailed Description