阅读说明：本技术 一种二烷基二硫代氨基甲酸酯的制备方法 (Preparation method of dialkyl dithiocarbamate ) 是由 张裕 于 2019-07-30 设计创作，主要内容包括：本发明公开了一种二烷基二硫代氨基甲酸酯的制备方法,其包括以下步骤,S1,在机械搅拌之下,向反应瓶中加入1重量份当量的二烷基胺和1.0-1.5重量份当量的氢氧化钠,再加入1.0-5.0重量份当量的乙醇,反应温度为20-90℃,搅拌均匀成混合溶液；S2,向步骤S1中所制得的混合溶液中缓慢滴加1.0-1.5重量份当量的二硫化碳与0.3-1.0重量份当量的溶剂A的混合溶液,滴加时间为1-5小时,滴加完毕后,将混合物加热至50-100℃,反应1-5小时,反应结束后,减压回收溶剂,再过滤除去无机盐,滤液进一步减压蒸馏即得到产物。本发明采用氢氧化钠的乙醇溶液代替氢氧化钠水溶液体系,二硫化碳和二氯甲烷采用同时滴加的方式,可以有效避免中间体钠盐析出终止反应,适合推广使用。(the invention discloses a preparation method of dialkyl dithiocarbamate, which comprises the following steps of S1, under the mechanical stirring, adding 1 weight part equivalent of dialkyl amine and 1.0-1.5 weight parts equivalent of sodium hydroxide into a reaction bottle, then adding 1.0-5.0 weight parts equivalent of ethanol, the reaction temperature is 20-90 ℃, and stirring uniformly to obtain a mixed solution; s2, slowly dripping a mixed solution of 1.0-1.5 weight parts of equivalent carbon disulfide and 0.3-1.0 weight parts of equivalent solvent A into the mixed solution prepared in the step S1 for 1-5 hours, heating the mixture to 50-100 ℃ after dripping is finished, reacting for 1-5 hours, recovering the solvent under reduced pressure after the reaction is finished, filtering to remove inorganic salt, and further distilling the filtrate under reduced pressure to obtain the product. According to the invention, the ethanol solution of sodium hydroxide is adopted to replace a sodium hydroxide aqueous solution system, and the carbon disulfide and the dichloromethane are simultaneously dropwise added, so that the intermediate sodium salt can be effectively prevented from precipitating and terminating the reaction, and the method is suitable for popularization and use.)

1. A process for preparing dialkyl dithio-carbamate, which comprises the following steps,

s1, under the mechanical stirring, adding 1 part by weight equivalent of dialkyl amine and 1.0-1.5 parts by weight equivalent of sodium hydroxide into a reaction bottle, then adding 1.0-5.0 parts by weight equivalent of ethanol, reacting at the temperature of 20-90 ℃, and uniformly stirring to obtain a mixed solution;

S2, slowly dripping a mixed solution of 1.0-1.5 weight parts of equivalent carbon disulfide and 0.3-1.0 weight parts of equivalent solvent A into the mixed solution prepared in the step S1 for 1-5 hours, heating the mixture to 50-100 ℃ after dripping is finished, reacting for 1-5 hours, recovering the solvent under reduced pressure after the reaction is finished, filtering to remove inorganic salt, and further distilling the filtrate under reduced pressure to obtain the product.

2. The method of claim 1, wherein the ratio of dialkylamine, sodium hydroxide, and carbon disulfide is 1.0: 1.2: 1.05.

3. The method for producing dialkyldithiocarbamates according to claim 1, wherein the solvent A is one or more mixed solvents of organic solvents.

4. The method for preparing dialkyldithiocarbamate according to claim 3, wherein the solvent A is dichloromethane or dichloroethane.

5. The method for preparing dialkyldithiocarbamate according to claim 4, wherein the solvent A is dichloromethane.

6. The method for preparing dialkyldithiocarbamates according to claim 1, wherein the dihydrocarbylamine is diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, or diisobutylamine.

7. The method for producing dialkyldithiocarbamates according to claim 6, wherein di-n-butylamine is used as the dihydrocarbylamine.

8. The method of any of claims 1-7, wherein the product is of the formula:

Wherein R is ethyl, n-propyl, isopropyl, n-butyl or isobutyl.

Technical Field

the invention relates to the technical field of dialkyl dithiocarbamate, in particular to a preparation method of dialkyl dithiocarbamate.

Background

With the increasing environmental protection requirements, the lubricating oil additive is developing towards low ash content, multiple functions, environmental friendliness and the like. Dialkyl dithiocarbamate is used as ashless antioxidant, extreme pressure and antiwear multifunctional additive and may be used widely in gear oil, hydraulic oil, compressor oil, metal processing liquid and lubricating grease. The representative product is methylene bis-dibutyl dithiocarbamate.

Through retrieval, the patent US015368 discloses a two-step synthetic route, and in the first step, dibutylamine, sodium hydroxide and water are mixed and then carbon disulfide is dripped to prepare an intermediate sodium salt solution; and secondly, dripping dichloromethane into the solution, reacting for several hours, separating a water phase, washing, and distilling under reduced pressure to obtain a product, wherein the method generates a large amount of salt-containing wastewater, and the patent CN1159294 discloses a one-step synthesis method, mixing di-n-butylamine, sodium hydroxide, water and ethanol, dripping carbon disulfide, reacting for several hours, extracting with gasoline, washing with water, and concentrating to obtain a product.

Disclosure of Invention

The invention aims to solve the defects in the prior art and provides a preparation method of dialkyl dithiocarbamate.

In order to achieve the purpose, the invention adopts the following technical scheme:

A method for preparing dialkyl dithiocarbamate comprises the following steps,

s1, under the mechanical stirring, adding 1 part by weight equivalent of dialkyl amine and 1.0-1.5 parts by weight equivalent of sodium hydroxide into a reaction bottle, then adding 1.0-5.0 parts by weight equivalent of ethanol, reacting at the temperature of 20-90 ℃, and uniformly stirring to obtain a mixed solution;

s2, slowly dripping a mixed solution of 1.0-1.5 weight parts of equivalent carbon disulfide and 0.3-1.0 weight parts of equivalent solvent A into the mixed solution prepared in the step S1 for 1-5 hours, heating the mixture to 50-100 ℃ after dripping is finished, reacting for 1-5 hours, recovering the solvent under reduced pressure after the reaction is finished, filtering to remove inorganic salt, and further distilling the filtrate under reduced pressure to obtain the product.

Preferably, the ratio of dialkylamine, sodium hydroxide and carbon disulfide is 1.0: 1.2: 1.05.

Preferably, the solvent A is one or more mixed solvents of organic solvents.

Preferably, the solvent A is dichloromethane or dichloroethane.

Preferably, the solvent A is dichloromethane.

preferably, the dialkyl amine is diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine or diisobutylamine.

preferably, di-n-butylamine is used as the dihydrocarbylamine.

Preferably, the product has the following structural formula:

Wherein R is ethyl, n-propyl, isopropyl, n-butyl or isobutyl.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, the ethanol solution of sodium hydroxide is adopted to replace a sodium hydroxide aqueous solution system, and the carbon disulfide and the dichloromethane are simultaneously dropwise added, so that the precipitation termination reaction of the intermediate sodium salt can be effectively avoided. The ethanol can be recycled, so that the salt-containing wastewater is avoided, the disposal cost is reduced, and the environmental and economic benefits are improved. Is suitable for popularization and application.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments.