阅读说明：本技术 一种羟基新戊腈的制备方法 (Preparation method of hydroxypivaonitrile ) 是由 蔡奇峰 汪洪湖 段小瑞 王凯 李涛 于 2019-11-28 设计创作，主要内容包括：本发明涉及一种羟基新戊腈的制备方法,其包括如下步骤：配制氰化钠水溶液,控制其温度在5～15℃条件下调pH值至6～8,向其中滴加温度60～70℃的羟基新戊醛水溶液,并控制混合溶液的温度在10～25℃的范围内,滴加结束后在20～30℃保温反应,得羟基新戊腈。本发明提供的方法以水为溶剂,未引入其它有机试剂,反应安全、环保,反应时间短,步骤简单,利于大规模生产。(The invention relates to a preparation method of hydroxypivaonitrile, which comprises the following steps: preparing a sodium cyanide aqueous solution, controlling the temperature of the sodium cyanide aqueous solution to be 5-15 ℃, adjusting the pH value to be 6-8, dropwise adding a hydroxypivalaldehyde aqueous solution with the temperature of 60-70 ℃, controlling the temperature of the mixed solution to be 10-25 ℃, and after dropwise adding, carrying out heat preservation reaction at 20-30 ℃ to obtain hydroxypivaonitrile. The method provided by the invention takes water as a solvent, does not introduce other organic reagents, is safe and environment-friendly in reaction, short in reaction time and simple in steps, and is beneficial to large-scale production.)

1. A preparation method of hydroxypivaonitrile is characterized by comprising the following steps: preparing a sodium cyanide aqueous solution, controlling the temperature of the sodium cyanide aqueous solution to be 5-15 ℃, adjusting the pH value to be 6-8, dropwise adding a hydroxypivalaldehyde aqueous solution with the temperature of 60-70 ℃, controlling the temperature of the mixed solution to be 10-25 ℃, and after dropwise adding, carrying out heat preservation reaction at 20-30 ℃ to obtain hydroxypivaonitrile.

2. The method according to claim 1, wherein the hydroxypivalaldehyde aqueous solution has a concentration of 65-70% by mass.

3. The method according to claim 1, wherein the concentration of the aqueous sodium cyanide solution is 25 to 30% by mass.

4. The method according to claim 1 or 3, wherein the pH is adjusted to 7 to 7.5 at 5 to 10 ℃.

5. The method according to claim 4, wherein the agent for adjusting the pH value is sulfuric acid with a concentration of 50-98%.

6. The method according to any one of claims 1 to 3, wherein the mass ratio of the aqueous sodium cyanide solution to the aqueous hydroxypivalaldehyde solution added dropwise thereto is (1 to 1.5): 1.

7. the method according to claim 1, wherein the temperature of the mixed solution is controlled within the range of 10 to 15 ℃ for dropwise addition, and the temperature is maintained at 20 to 25 ℃ for reaction after the dropwise addition.

8. The method according to claim 1, wherein the temperature of the mixed solution is controlled within the range of 15 to 20 ℃ for dropwise addition, and after the dropwise addition, the reaction is carried out while maintaining the temperature at 25 to 30 ℃.

9. The method according to claim 1, 7 or 8, wherein the incubation reaction time is 4-8 h.

10. The method of claim 1, comprising the steps of: preparing a sodium cyanide aqueous solution, controlling the temperature of the sodium cyanide aqueous solution to be 5-10 ℃ and regulating the pH value to be 7-7.5, dropwise adding a hydroxypivalaldehyde aqueous solution with the temperature of 60-70 ℃, controlling the temperature of the mixed solution to be 10-20 ℃, and after dropwise adding, keeping the temperature at 20-25 ℃ for reacting for 4-8 hours to obtain hydroxypivaonitrile.

Technical Field

The invention relates to the field of chemical production, and particularly relates to a preparation method of hydroxypivaonitrile.

Background

The chemical name of hydroxypivalaldehyde is 2, 2-dimethyl-3-hydroxypropanal, abbreviated as HPA, and is a key intermediate for synthesizing novel efficient antioxidant AO-80, hydroxypivalic acid, hydroxypivalyl hydroxypivalate, hydroxypentanamide, neopentyl glycol and the like by a hydrogenation method. At present, the synthesis process of hydroxypivalaldehyde at home and abroad is generally synthesized by an aldol condensation method, formaldehyde aqueous solution and isobutyraldehyde are used as raw materials, and the applied catalyst mainly comprises the following components: organic tertiary amines such as alkali metal hydroxides, alkali metal carbonates, and triethylamine, and anion exchange resins.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a method for preparing hydroxypivaonitrile, which is simple and convenient to operate and is green and environment-friendly.

Specifically, the method for preparing hydroxypivaonitrile provided by the invention comprises the following steps: preparing a sodium cyanide aqueous solution, controlling the temperature of the sodium cyanide aqueous solution to be 5-15 ℃, adjusting the pH value to be 6-8, dropwise adding a hydroxypivalaldehyde aqueous solution with the temperature of 60-70 ℃, controlling the temperature of the mixed solution to be 10-25 ℃, and after dropwise adding, carrying out heat preservation reaction at 20-30 ℃ to obtain hydroxypivaonitrile.

In order to improve the reaction efficiency, the invention preferably selects the mass percentage concentration of the hydroxypivalaldehyde aqueous solution to be 65-70%. The mass percentage concentration of the sodium cyanide aqueous solution is 25-30%. The mass ratio of the sodium cyanide aqueous solution to the hydroxypivalaldehyde aqueous solution dropwise added thereto is (1-1.5): 1.

the invention converts sodium cyanide solution into hydrocyanic acid by adjusting pH value. The pH value after the adjustment is preferably 7-7.5. In actual operation, the reagent for adjusting the pH value can adopt sulfuric acid with the concentration of 50-98%.

The invention ensures that the reaction is carried out efficiently under the condition of only using water as a solvent and without adding other catalysts by controlling the mixing mode and the temperature of the two raw material solutions.

As a preferable scheme of the invention, the temperature of the mixed solution is controlled within the range of 10-15 ℃ for dropwise addition, and after the dropwise addition is finished, the reaction is carried out at the temperature of 20-25 ℃; the time of the heat preservation reaction is preferably 4-8 h, and the reaction can be basically completed within 4 h.

As a preferable scheme of the invention, the temperature of the mixed solution is controlled within the range of 15-20 ℃ for dropwise addition, and after the dropwise addition is finished, the heat preservation reaction is carried out at 25-30 ℃; the time of the heat preservation reaction is preferably 4-8 h, and the reaction can be basically completed within 4 h.

As a preferred embodiment of the present invention, the method comprises the steps of:

(1) dissolving 120-125 parts of hydroxypivalaldehyde in 50-70 parts of water, and keeping the temperature at 60-70 ℃ for later use;

(2) dissolving 60-65 parts of sodium cyanide in 150-170 parts of water, controlling the temperature of the water to be 5-10 ℃, adjusting the pH value to 7-7.5, dropwise adding the solution obtained in the step (1), controlling the temperature of the mixed solution to be 10-20 ℃, and preserving the temperature at 20-25 ℃ for 4-8 hours after dropwise adding to obtain the hydroxypivaonitrile.

In the scheme, the parts are parts by mass and can be mass units commonly used in the field such as g, kg and the like.

Compared with the prior art, the method takes Hydroxypivalaldehyde (HPA) as a raw material, and prepares hydroxypivaonitrile by adding cyanogen. The method provided by the invention uses water as a solvent in the whole process, does not introduce other organic reagents, is safe and environment-friendly in reaction, short in reaction time and simple in steps, and is beneficial to large-scale production.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.