阅读说明：本技术 一种丙二腈的合成方法 (Synthesis method of malononitrile ) 是由 梁海 杨国民 王玉 金炳旭 周琦 刘晗 高宏宇 于 2019-10-23 设计创作，主要内容包括：本发明属于有机合成技术领域,提供了一种丙二腈的合成方法,步骤如下：按照摩尔比为1:1～3:1,将二氯甲烷和氰化钠添加到反应釜内,在搅拌条件和加热条件下,缓慢向反应釜内加入催化剂,控制反应釜内温度在90℃,加料结束后继续保温5-9h；反应结束后向反应产物中添加去离子水多次洗涤有机相,分离出有机相,对有机相干燥、精馏后得到丙二腈；所述的催化剂为三氯化铝与四丁基溴化铵的组合物。本发明采用廉价的二氯甲烷为原料一步法直接合成了丙二腈产品,工艺路线简单、成本低。(The invention belongs to the technical field of organic synthesis, and provides a method for synthesizing malononitrile, which comprises the following steps: adding dichloromethane and sodium cyanide into a reaction kettle according to a molar ratio of 1: 1-3: 1, slowly adding a catalyst into the reaction kettle under stirring and heating conditions, controlling the temperature in the reaction kettle at 90 ℃, and continuing to keep the temperature for 5-9 hours after the addition is finished; adding deionized water into the reaction product after the reaction is finished to wash an organic phase for multiple times, separating the organic phase, drying and rectifying the organic phase to obtain malononitrile; the catalyst is a composition of aluminum trichloride and tetrabutylammonium bromide. The method adopts cheap dichloromethane as a raw material to directly synthesize the malononitrile product by a one-step method, and has simple process route and low cost.)

1. The synthesis method of malononitrile is characterized by comprising the following steps:

adding dichloromethane and sodium cyanide into a reaction kettle according to a molar ratio of 1: 1-3: 1, slowly adding a catalyst into the reaction kettle under stirring and heating conditions, controlling the temperature in the reaction kettle at 90 ℃, and continuing to keep the temperature for 5-9 hours after the addition is finished; adding deionized water into the reaction product after the reaction is finished to wash an organic phase for multiple times, separating the organic phase, drying and rectifying the organic phase to obtain malononitrile; the catalyst is a composition of aluminum trichloride and tetrabutylammonium bromide.

2. The method for synthesizing malononitrile according to claim 1, wherein m (NaCN): m (tetrabutylammonium bromide): 1: 0.01-1: 0.2, and n (NaCN): n (AlCl)₃)＝1:0.5～1:2。

Technical Field

The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing malononitrile.

Background

Malononitrile is an important fine chemical intermediate for organic synthesis, gold leaching agent. In the aspect of medicine, the compound is a series of important drug intermediates for synthesizing vitamin B1, aminopterin, triamterene and the like. The dye, the pesticide and other aspects have important application. Can also be used as an extractant for gold. China is mainly used for producing products of triamterene, bensulfuron-methyl, 1,4,5, 8-naphthalene tetracarboxylic acid and pyrimidine series.

The traditional malononitrile synthesis process mainly comprises two reaction methods, namely, a reaction method of acetonitrile and chlorocyanogen. The method for preparing malononitrile by using the chlorocyanogen as a raw material and reacting the chlorocyanogen with acetonitrile has low yield and has not realized industrialization. Reacting ethyl cyanoacetate with ammonia at the temperature of below 20 ℃, cooling in an ice bath for 2 hours, filtering out a precipitate, washing a filter cake with ice water, recrystallizing with ethanol to obtain cyanoacetamide, reacting cyanoacetamide with phosphorus pentoxide, distilling under reduced pressure, collecting fractions below 110-120 ℃ as a crude product, and distilling under reduced pressure to obtain a finished product.

Disclosure of Invention

Aiming at the actual situation, the invention provides a method for synthesizing malononitrile, which takes cheap dichloromethane as a raw material to react with sodium cyanide, directly synthesizes malononitrile by a one-step method and has a simple route.

The technical scheme of the invention is as follows:

a method for synthesizing malononitrile comprises the following steps:

adding dichloromethane and sodium cyanide into a reaction kettle according to a molar ratio of 1: 1-3: 1, slowly adding a catalyst into the reaction kettle under stirring and heating conditions, controlling the temperature in the reaction kettle at 90 ℃, and continuing to keep the temperature for 5-9 hours after the addition is finished; adding deionized water into the reaction product after the reaction is finished to wash an organic phase for multiple times, separating the organic phase, drying and rectifying the organic phase to obtain malononitrile; the catalyst is a composition of aluminum trichloride and tetrabutylammonium bromide.

The catalyst is added in an amount of m (NaCN): m (tetrabutylammonium bromide): 1: 0.01-1: 0.2, and n (NaCN): n (AlCl)₃)＝1:0.5～1:2。

The invention has the beneficial effects that: the malononitrile product is directly synthesized by adopting cheap dichloromethane as a raw material through a one-step method, and the method has the advantages of simple process route and low cost.

Detailed Description

The following further describes the specific embodiments of the present invention in combination with the technical solutions.