阅读说明：本技术 一种o-3-氯-2-丙烯基羟胺游离碱的制备工艺 (Preparation process of O-3-chloro-2-propenyl hydroxylamine free alkali ) 是由 刘鹏 王蕾 张玉天 于 2020-12-02 设计创作，主要内容包括：本发明公开一种O-3-氯-2-丙烯基羟胺游离碱的制备工艺,过程如下：向反应釜中依次加入二苯甲酮和盐酸羟胺、醋酸钠、甲醇,升温反应完毕,向其中加入氢氧化钠溶液及1,3-二氯丙烯,升温反应完毕,过滤所得粗品加入盐酸溶液中,水解完毕,减压下除去有机溶剂,过滤回收二苯甲酮套用。开启搅拌,向其中加入二氯甲烷,分层,有机相脱溶回收二氯甲烷,水相加入氢氧化钠溶液调节pH值。碱解结束后,以二氯甲烷萃取产品,脱溶得到O-3-氯-2-丙烯基羟胺。O-3-氯-2-丙烯基羟胺游离碱的制备工艺总收率>74%,气相纯度>98%。该工艺操作简便,容易实现,原料便宜易得,且原料二苯甲酮可以循环利用,反应条件温和,安全环保。(The invention discloses a preparation process of O-3-chloro-2-propenyl hydroxylamine free alkali, which comprises the following steps: adding benzophenone, hydroxylamine hydrochloride, sodium acetate and methanol into a reaction kettle in sequence, after the temperature rise reaction is finished, adding a sodium hydroxide solution and 1, 3-dichloropropene into the reaction kettle, after the temperature rise reaction is finished, filtering to obtain a crude product, adding the crude product into a hydrochloric acid solution, after the hydrolysis is finished, removing an organic solvent under reduced pressure, and filtering to recover the benzophenone for reuse. Stirring, adding dichloromethane, demixing, desolventizing the organic phase to recover dichloromethane, and adding sodium hydroxide solution into the aqueous phase to adjust the pH value. After the alkaline hydrolysis is finished, extracting a product by using dichloromethane, and carrying out desolventizing to obtain the O-3-chloro-2-propenyl hydroxylamine. The total yield of the preparation process of the O-3-chloro-2-propenyl hydroxylamine free alkali is more than 74 percent, and the gas phase purity is more than 98 percent. The process is simple and convenient to operate, easy to implement, cheap and easily available in raw materials, capable of recycling the raw material benzophenone, mild in reaction conditions, safe and environment-friendly.)

1. A preparation process of O-3-chloro-2-propenyl hydroxylamine free alkali is characterized by comprising the following preparation route:

the specific process is as follows:

(1) preparation of benzophenone oxime: sequentially adding methanol, benzophenone, hydroxylamine hydrochloride and sodium acetate into a reaction kettle, and refluxing until the reaction is finished to obtain a benzophenone oxime solution;

(2) preparation of (E) -benzophenone O- (3-chloroallyloxy) oxime: transferring the reaction liquid obtained in the step (1) to another reaction kettle in vacuum, adding a sodium hydroxide solution and 1, 3-dichloropropene into the reaction kettle, heating to 50-55 ℃ for reaction, and filtering to obtain a crude product of (E) -benzophenone O- (3-chloroallyloxy) oxime for later use after the reaction is finished;

(3) preparation of O-3-chloro-2-propenyl hydroxylamine hydrochloride: adding the (E) -benzophenone O- (3-chloroallyloxy) oxime crude product prepared in the step (2) into a hydrochloric acid solution, reducing pressure to remove an organic solvent in a system after hydrolysis is finished, and filtering to recover benzophenone for reuse;

(4) preparation of O-3-chloro-2-propenyl hydroxylamine: and (3) transferring the reaction liquid prepared in the step (3) to another reaction kettle in vacuum, starting stirring, adding dichloromethane into the reaction liquid, layering, removing the solvent from the organic phase, recovering dichloromethane, adding sodium hydroxide solution into the water phase, adjusting the pH value, performing alkaline hydrolysis, extracting the product with dichloromethane after the alkaline hydrolysis is finished, and removing the solvent to obtain the O-3-chloro-2-propenyl hydroxylamine.

2. The process for preparing O-3-chloro-2-propenylhydroxylamine free base according to claim 1, wherein the molar ratio of benzophenone, hydroxylamine hydrochloride and sodium acetate in step (1) is 1 (1-2) to 2.

3. The process for preparing O-3-chloro-2-propenylhydroxylamine free base according to claim 1, wherein in the step (2) and the step (4), the mass concentration of the aqueous solution of sodium hydroxide is 28 to 35%; and (3) in the step (2) and the step (4), adding a sodium hydroxide aqueous solution, and adjusting the pH value of the system to 7-9.5.

4. The process for producing O-3-chloro-2-propenyl hydroxylamine free base according to claim 1, wherein the molar ratio of the benzophenone oxime to the 1, 3-dichloropropene is 1:0.95 to 1.1.

5. The process for producing O-3-chloro-2-propenylhydroxylamine free base according to claim 1, wherein in the step (3), the hydrochloric acid solution is added at 35 to 45 ℃ at a concentration of 32 to 38% by mass, and the pH of the system is 1 to 3 after the hydrochloric acid solution is added.

Technical Field

The invention belongs to the field of organic synthesis, and particularly relates to a preparation process of O-3-chloro-2-propenyl hydroxylamine free alkali.

Background

O-3-chloro-2-propenyl hydroxylamine, also known as chloramine, is an important intermediate in the production of clethodim. Clethodim is a broad-spectrum post-emergence herbicide for preventing and killing gramineous weeds in broad-leaved crops, which is proposed by Chevron chemical company in the United states, has strong killing effect on various annual and perennial weeds, and has little or no activity on dicotyledons or nutgrass flatsedge. O-3-chloro-2-propenyl hydroxylamine is also widely used in other cyclohexenone oxime herbicides such as tralkoxydim, cycloxydim, tralkoxydim and the like.

At present, the preparation methods of O-3-chloro-2-propenyl hydroxylamine reported at home and abroad mainly comprise the following steps:

1. acetonitrile and ethanol are used as starting materials to obtain a reaction intermediate ethyl acetylhydroxamate, and the reaction intermediate ethyl acetylhydroxamate is hydrolyzed to obtain O-3-chloro-2-propenyl hydroxylamine. The method uses a large amount of hydrogen chloride gas, the pollution and corrosion are serious, and the used tetrabutyl ammonium bromide phase transfer catalyst is expensive, so that the method is not beneficial to industrial production from the aspects of environmental protection and cost. Therefore, this method is rarely adopted at present.

2. Acetone is used as a starting material to obtain a reaction intermediate acetone oxime ether, and the acetone oxime ether is hydrolyzed to obtain O-3-chloro-2-propenyl hydroxylamine, as described in patents US5382685 and US 5488162. The method needs a rectification device and controls a certain reflux ratio to continuously remove the generated acetone, has complex and tedious operation, and is easy to explode at an over-temperature in the production process, so a certain safety problem exists.

3. Methyl acetate or ethyl acetate is used as a starting material to obtain a reaction intermediate propenyl hydroxylamine protected by acetyl, and the propenyl hydroxylamine is hydrolyzed to obtain O-3-chloro-2-propenyl hydroxylamine. The raw materials of the method are cheap and easy to obtain, but the solvent after reaction contains a large amount of ethanol or methanol, so that the solvent is difficult to recover.

4. To be provided withNThe-hydroxyphthalimide is used as a starting material and is hydrolyzed to obtain O-3-chloro-2-propenyl hydroxylamine.NThe synthesis method of the-hydroxyphthalimide mainly takes phthalic anhydride and phthalic acid as initial raw materials. As described in patent CN1051170, phthalic anhydride is used as a starting material and is finally converted into phthalic acid, which cannot be recycled. As described in patent CN105348139, the use of phthalic acid as a starting material can lead to the recycling of the starting material, but the process requires the conversion of phthalic acid to phthaloyl chloride in the presence of thionyl chloride and the distillation of excess thionyl chloride, which complicates the operation of the process.

The final results reported in the above documents are all in the form of O-3-chloro-2-propenyl hydroxylamine hydrochloride. The product in the form of the hydrochloride salt presents two problems: a certain amount of hydroxylamine hydrochloride is included in the O-3-chloro-2-propenyl hydroxylamine hydrochloride, and the reaction activity of the hydroxylamine hydrochloride and corresponding aldehyde or ketone is higher, so that a certain amount of by-products are generated, and the quality control of a final product is influenced. On the other hand, the aqueous solution of O-3-chloro-2-propenyl hydroxylamine hydrochloride is unstable and needs to be stored below 15 ℃ or degradation products are gradually formed.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a preparation process of O-3-chloro-2-propenyl hydroxylamine free alkali suitable for industrial production, the process is simple and convenient to operate and easy to realize, the raw materials are cheap and easy to obtain, the raw material benzophenone can be recycled, the reaction condition is mild, and the preparation process is safe and environment-friendly.

The preparation process of the O-3-chloro-2-propenyl hydroxylamine free alkali comprises the following steps:

the method specifically comprises the following steps:

(1) preparation of benzophenone oxime: sequentially adding methanol, benzophenone, hydroxylamine hydrochloride and sodium acetate into a reaction kettle, heating for reflux reaction, and obtaining a benzophenone oxime solution after the reaction is finished;

(2) preparation of (E) -benzophenone O- (3-chloroallyloxy) oxime: transferring the solution of the benzophenone oxime prepared in the step (1) to another reaction kettle in vacuum, adding a sodium hydroxide solution and 1, 3-dichloropropene into the reaction kettle, heating for reaction, and filtering to obtain a crude product of (E) -benzophenone O- (3-chloroallyloxy) oxime for later use after the reaction is finished;

(3) preparation of O-3-chloro-2-propenyl hydroxylamine hydrochloride: adding the (E) -benzophenone O- (3-chloroallyloxy) oxime crude product prepared in the step (2) into a hydrochloric acid solution, removing an organic solvent in a system under reduced pressure after hydrolysis is finished, and filtering and recovering benzophenone for reuse;

(4) preparation of O-3-chloro-2-propenyl hydroxylamine: and (3) transferring the reaction liquid prepared in the step (03) to another reaction kettle in vacuum, starting stirring, adding dichloromethane into the reaction liquid, layering, removing the solvent from the organic phase to recover dichloromethane, adding sodium hydroxide solution into the water phase to adjust the pH value, extracting the product with dichloromethane after the alkaline hydrolysis is finished, and removing the solvent (recovering dichloromethane) to obtain the O-3-chloro-2-propenyl hydroxylamine.

Wherein the molar ratio of the benzophenone, the hydroxylamine hydrochloride and the sodium acetate in the step (1) is 1 (1-2) to 2.

Preferably, in the step (2) and the step (4), the mass concentration of the sodium hydroxide aqueous solution is 28-35%; and (3) in the step (2) and the step (4), adding a sodium hydroxide aqueous solution, and adjusting the pH value of the system to 7-9.5.

Preferably, in the step (2), the molar ratio of the benzophenone oxime to the 1, 3-dichloropropene is 1: 0.95-1.1.

Preferably, in the step (3), the mass concentration of the hydrochloric acid solution is 32-38%, the hydrochloric acid solution is added at 35-45 ℃, and the pH of the system is 1-3 after the hydrochloric acid solution is added.

In the steps (1), (2) and (3), the central control detection method is HPLC.

In the step (4), the central control detection method is GC.

The invention has the advantages and positive effects that: the preparation process of the O-3-chloro-2-propenyl hydroxylamine provided by the invention has the advantages of short process route, simple and convenient operation, easy realization, cheap and easily obtained raw materials, mild reaction conditions and cyclic utilization of the raw material benzophenone. The whole process is safe and environment-friendly. The purity of the final product O-3-chloro-2-propenyl hydroxylamine can reach 99%.

Drawings

FIG. 1 is a diagram of the final product obtained in example 1¹An H-NMR spectrum;

FIG. 2 is a GC plot of the final product made in example 1;

FIG. 3 is a GC plot of the final product made in example 2;

FIG. 4 is a GC plot of the final product made in example 3.

Detailed Description

In order to further explain the contents and features of the present invention, the following description is given with reference to the examples.

Example 1

A preparation process of O-3-chloro-2-propenyl hydroxylamine free alkali comprises the following steps:

(1) preparation of benzophenone oxime: adding 900 g of methanol into a reaction kettle, sequentially adding 91 g of benzophenone, 56 g of hydroxylamine hydrochloride and 1.0 mol of sodium acetate, heating to 65 ℃, carrying out reflux reaction, monitoring by HPLC, and obtaining a benzophenone oxime solution after the reaction is finished;

(2) preparation of (E) -benzophenone O- (3-chloroallyloxy) oxime: and (2) preparing a reaction kettle, vacuumizing to reduce the pressure to be below 0.06 MP, transferring the solution of the benzophenone oxime prepared in the step (1) into the reaction kettle through a pipeline, and adding 28wt% of sodium hydroxide solution into the reaction kettle to adjust the pH value to be within the range of 7.5-9.5 after the transfer is finished. Then 1, 3-dichloropropene (55 g, 0.50 mol) is added dropwise, and the temperature is raised to 50-55 ℃ after the dropwise addition is finished for reaction. Monitoring by HPLC, after the reaction is finished, filtering to obtain a crude product of (E) -benzophenone O- (3-chloroallyloxy) oxime for later use;

(3) preparation of O-3-chloro-2-propenyl hydroxylamine hydrochloride: and (3) controlling the temperature of the (E) -benzophenone O- (3-chloroallyloxy) oxime crude product prepared in the step (2) to 35-45 ℃, adding the crude product into 35wt% hydrochloric acid solution (400 mL), performing hydrolysis reaction with the system pH value of 1-3 after the dropwise addition is finished, and after 2 hours, monitoring the hydrolysis completion by HPLC. Most of the organic solvent in the system is removed under reduced pressure, the filter cake obtained by filtering is the benzophenone, and the recycling can be realized after drying at 40 ℃.

(4) Preparation of O-3-chloro-2-propenyl hydroxylamine: and (3) transferring the reaction liquid prepared in the step (3) into another reaction kettle through the vacuum operation in the step (2), starting stirring, adding 800 g of dichloromethane into the reaction kettle, layering, removing the solvent from the organic phase to recover dichloromethane, and adding 28wt% of sodium hydroxide solution into the water phase to adjust the pH value to be within the range of 7-9 for alkaline hydrolysis. After 3 hours, GC monitored the end of the alkaline hydrolysis, the product was extracted with dichloromethane (600 g x 3), the organic phases were combined, dried over anhydrous sodium sulfate, filtered and the solvent removed (dichloromethane recovered) to yield 40.9 g (liquid) of finished O-3-chloro-2-propenyl hydroxylamine in an overall yield of 76%, as shown in figure 2, with a purity of 99.2% by GC.

The hydrogen spectrum of the finished O-3-chloro-2-propenyl hydroxylamine product is shown in FIG. 1,¹HNMR (Bruker, 400M, CDCl₃): δ6.26(d, 1H, 13.6Hz), 6.05(d, 1H, 6.8Hz), 5.42(s, 2H), 4.12(m, 2H).

example 2

A preparation process of O-3-chloro-2-propenyl hydroxylamine free alkali comprises the following steps:

(1) preparation of benzophenone oxime: adding 500 g of methanol into a reaction kettle, sequentially adding benzophenone (50 g, 0.27 mol), hydroxylamine hydrochloride (31 g, 0.45 mol) and sodium acetate (45 g, 0.55 mol), heating to 65 ℃, carrying out reflux reaction, monitoring by HPLC (high performance liquid chromatography), and obtaining a benzophenone oxime solution after the reaction is finished;

(2) preparation of (E) -benzophenone O- (3-chloroallyloxy) oxime: and (2) preparing a reaction kettle, reducing the pressure of the reaction kettle to be below 0.06 MP through vacuum, transferring the solution of the benzophenone oxime prepared in the step (1) into the reaction kettle through a pipeline, and adding 30wt% of sodium hydroxide solution into the reaction kettle to adjust the pH value to be in a range of 7-9. Then dropwise adding 1, 3-dichloropropene (30.5 g, 0.27 mol), heating to 50-55 ℃ for reaction, monitoring by HPLC, and filtering to obtain a crude product of (E) -benzophenone O- (3-chloroallyloxy) oxime for later use after the reaction is finished;

(3) preparation of O-3-chloro-2-propenyl hydroxylamine hydrochloride: and (3) controlling the temperature of the (E) -benzophenone O- (3-chloroallyloxy) oxime crude product prepared in the step (2) to be 35-45 ℃, adding the crude product into a hydrochloric acid solution (250 mL) of a 32wt% hydrochloric acid solution, performing hydrolysis reaction with the system pH of 1-3 after the dropwise addition is finished, and after 2 hours, monitoring the hydrolysis completion by HPLC. Most of organic solvent in the system is removed under reduced pressure, filter cake obtained by filtering is benzophenone, and the benzophenone can be recycled after being dried at 40 ℃;

(4) preparation of O-3-chloro-2-propenyl hydroxylamine: transferring the reaction liquid prepared in the step (3) into another reaction kettle through the vacuum operation in the step (2), starting stirring, adding 440 g of dichloromethane into the reaction kettle, layering, removing the solvent from the organic phase to recover dichloromethane, and adding 30wt% of sodium hydroxide solution into the water phase to adjust the pH value to be 7-9.5 for alkaline hydrolysis. After 3 hours, GC monitored the end of the alkaline hydrolysis, the product was extracted with dichloromethane (350 g x 3), the organic phases were combined, dried over anhydrous sodium sulfate, filtered and the solvent removed (dichloromethane recovered) to yield 21.8 g of finished O-3-chloro-2-propenyl hydroxylamine in a total yield of 74%, as shown in figure 3, having a purity of 99.8% by GC.

Example 3

A preparation process of O-3-chloro-2-propenyl hydroxylamine free alkali comprises the following steps:

(1) preparation of benzophenone oxime: adding 1.5 kg of methanol into a reaction kettle, then sequentially adding benzophenone (150 g, 0.82 mol), hydroxylamine hydrochloride (92 g, 1.32 mol) and sodium acetate (135 g, 1.65 mol), heating to 65 ℃ for reflux reaction, monitoring by HPLC, and obtaining a benzophenone oxime solution after the reaction is finished;

(2) preparation of (E) -benzophenone O- (3-chloroallyloxy) oxime: and (2) preparing a reaction kettle, reducing the pressure of the reaction kettle to be below 0.06 MP by vacuum, transferring the solution of the benzophenone oxime prepared in the step (1) into the reaction kettle through a pipeline, and adding 35wt% of sodium hydroxide solution into the reaction kettle to adjust the pH value to be in the range of 7.5-9. Then dropwise adding 1, 3-dichloropropene (90.7 g, 0.82 mol), heating to 50-55 ℃ after dropwise adding, reacting, monitoring by HPLC, filtering to obtain a crude product of (E) -benzophenone O- (3-chloroallyloxy) oxime for later use after the reaction is finished;

(3) preparation of O-3-chloro-2-propenyl hydroxylamine hydrochloride: and (3) controlling the temperature of the (E) -benzophenone O- (3-chloroallyloxy) oxime crude product prepared in the step (2) to be 35-45 ℃, adding the crude product into 35wt% hydrochloric acid solution (600 mL), controlling the pH value to be within a range of 1-3 to perform hydrolysis reaction after the dropwise addition is finished, and monitoring the hydrolysis completion by HPLC after 2 hours. Most of the organic solvent in the system is removed under reduced pressure, the filter cake obtained by filtering is the benzophenone, and the recycling can be realized after drying at 40 ℃.

(4) Preparation of O-3-chloro-2-propenyl hydroxylamine: transferring the reaction liquid prepared in the step (3) into another reaction kettle through the vacuum operation in the step (2), starting stirring, adding 1300 g of dichloromethane into the reaction kettle, layering, desolventizing the organic phase to recover dichloromethane, and adding 35wt% of sodium hydroxide solution into the water phase to adjust the pH value to be within the range of 7-9. After 3 hours, GC monitored the end of the alkaline hydrolysis, the product (900 g x 3) was extracted with dichloromethane, the organic phases combined, dried over anhydrous sodium sulfate, filtered and the solvent removed to give 66.7 g of finished O-3-chloro-2-propenyl hydroxylamine in a total yield of 75.4% with a purity of 99.1% as indicated in figure 4 by GC.

The above examples are only for further illustration of the present invention and are not intended to limit the present invention, and all equivalent implementations of the present invention should be included within the scope of the claims of the present invention.