阅读说明：本技术 一种苯乙基异硫氰酸酯的制备方法 (Preparation method of phenethyl isothiocyanate ) 是由 王冠 吴兵 于 2019-10-30 设计创作，主要内容包括：本发明涉及一种苯乙基异硫氰酸酯的制备方法。本发明苯乙基异硫氰酸酯制备方法是以苯乙胺和二硫化碳为原料,以三乙胺作为碱首先生成二硫代氨基甲酸盐,然后使用对甲苯磺酰氯进行脱硫,于是得到苯乙基异硫氰酸酯。与现有技术相比,本发明合成方法使用的原料更加便宜、易于运输、安全性高、且反应条件相对温和、反应收率高,因此,本发明解决了现有技术存在的转化率不高、脱硫剂沸点低、毒性大,运输极其不安全、产品成本高等问题。(The invention relates to a preparation method of phenethyl isothiocyanate. The preparation method of the phenethyl isothiocyanate takes phenethylamine and carbon disulfide as raw materials, takes triethylamine as alkali to firstly generate dithiocarbamate, and then uses p-toluenesulfonyl chloride to desulfurize, thus obtaining the phenethyl isothiocyanate. Compared with the prior art, the synthesis method has the advantages of cheaper raw materials, easiness in transportation, high safety, relatively mild reaction conditions and high reaction yield, and therefore, the problems of low conversion rate, low boiling point of the desulfurizer, high toxicity, extremely unsafe transportation, high product cost and the like in the prior art are solved.)

1. A preparation method of phenethyl isothiocyanate is characterized by comprising the following steps:

under the protection of nitrogen, phenylethylamine, triethylamine and tetrahydrofuran are mixed according to a molar ratio of 1: 1-4: 5-15 to obtain a mixture, and then in an ice water bath, mixing the mixture according to a molar ratio of phenylethylamine to carbon disulfide of 1: 1-2, dropwise adding carbon disulfide into the mixture by using a peristaltic pump, keeping the temperature at 0-5 ℃ for reaction, uniformly mixing, gradually heating to room temperature, and reacting at the temperature for 1-3 hours to obtain a reaction solution;

dropwise adding p-toluenesulfonyl chloride into the reaction liquid in an ice water bath according to the molar ratio of phenethylamine to p-toluenesulfonyl chloride of 1: 1-1.5, uniformly mixing, heating to room temperature, reacting for 0.5-2.0 h at the temperature, and adding phenethylamine, hydrochloric acid and methyl tert-butyl ether into the obtained reaction liquid according to the molar ratio of 1: 0.8-1.2: and (3) adding hydrochloric acid and methyl tert-butyl ether to 8.0-12.0, mixing and extracting, desolventizing the extracted organic phase, and distilling to obtain the phenethyl isothiocyanate.

2. The process according to claim 1, wherein the molar ratio of phenylethylamine, triethylamine and tetrahydrofuran is 1: 1.8-3.2: 8 to 12.

3. The process according to claim 1, wherein the molar ratio of phenylethylamine to carbon disulfide is 1:1.2 to 1.8.

4. The method according to claim 1, wherein the molar ratio of phenylethylamine to p-toluenesulfonyl chloride is 1:1.2 to 1.4.

5. The process according to claim 1, wherein the molar ratio of phenylethylamine, hydrochloric acid and methyl tert-butyl ether is 1: 0.9-1.1: 9.0 to 11.0.

6. The method according to claim 1, wherein the hydrochloric acid concentration in the mixture of phenethylamine, hydrochloric acid and methyl t-butyl ether is 5 to 10% by weight.

7. The method according to claim 1, wherein the desolventizing step comprises heating the washed combined organic phase at a temperature of 40-70 ℃ to remove the solvent contained therein.

8. The process according to claim 1, wherein the organic phase is distilled under a pressure of 0.2 to 0.3KPa at a temperature of 110 to 130 ℃ and at a temperature of 110 to 130 ℃ to remove impurities contained therein, thereby obtaining phenethyl isothiocyanate having a content of 80.0 to 99.0% by weight.

[ technical field ] A method for producing a semiconductor device

The invention belongs to the technical field of chemical synthesis. More particularly, the invention relates to a preparation method of phenethyl isothiocyanate.

[ background of the invention ]

Isothiocyanate is a compound containing R-N-C-S structure, and is a glucosinolate enzymolysis product abundantly existing in cruciferous plants and related plants of Capparidaceae (such as broccoli, cabbage, etc.). It can be divided into three major classes, aromatic, aliphatic and indole, according to different side chain structures. Isothiocyanate is widely used as a food flavoring agent and a preservative in foreign countries due to its special pungent flavor. Increasing researchers have generated a great deal of interest in its bacteriostatic properties in an attempt to apply it to food packaging. In addition, the isothiocyanate has high biological activity, such as sterilization, platelet aggregation inhibition, antioxidation and the like, is also the main anti-tumor active component of cruciferous vegetables, and is an effective cancer inhibitor. Can be used for treating antibacterial, anti-inflammatory and cancer diseases. The isothiocyanate also has good insecticidal and weeding effects in agriculture, so the isothiocyanate is a main raw material for manufacturing the biological pesticide.

Because of the wide application of isothiocyanate, the market demand of isothiocyanate is very large. The extraction method for obtaining isothiocyanate from plants is not enough to meet the market demand, so that the problem of seeking for economic green chemical synthesis method for producing isothiocyanate becomes an urgent need to be solved.

Currently, there are two main methods for producing phenethyl isothiocyanate: a method for one-step production of phenethyl isothiocyanate from phenethylamine and thiophosgene in chloroform. The raw material thiophosgene used by the method needs to be produced by self, so that the method has high danger and great environmental protection pressure. And the other one is that phenethylamine and carbon disulfide are used as raw materials, triethylamine is used as alkali to firstly generate thiocarbamate, and then a desulfurizer is used for desulfurization to generate phenethyl isothiocyanate. The production route is relatively mild. The choice of the desulfurizing agent is critical in this route. Tert-butyl carbonic acid diethyl phosphoric anhydride is used as a desulfurizing agent, but the conversion rate is not high, so that the production cost is high. Methyl chloroformate has also been used as a desulfurizing agent, but this compound has a low boiling point, is toxic, and is extremely unsafe to transport, and its transportation cost also increases the product cost.

Therefore, in view of the technical defects of the prior art, the present inventors have completed the present invention by summarizing the prior art through a large number of experimental studies and analyses.

[ summary of the invention ]

[ problem to be solved ]

The invention aims to provide a preparation method of phenethyl isocyanate.

[ solution ]

The invention is realized by the following technical scheme.

The invention relates to a preparation method of phenethyl isocyanate.

The preparation method comprises the following steps:

under the protection of nitrogen, phenylethylamine, triethylamine and tetrahydrofuran are mixed according to a molar ratio of 1: 1-4: 5-15 to obtain a mixture, and then in an ice water bath, mixing the mixture according to a molar ratio of phenylethylamine to carbon disulfide of 1: 1-2, dropwise adding carbon disulfide into the mixture by using a peristaltic pump, keeping the temperature at 0-5 ℃ for reaction, uniformly mixing, gradually heating to room temperature, and reacting at the temperature for 1-3 hours to obtain a reaction solution;

dropwise adding p-toluenesulfonyl chloride into the reaction liquid in an ice water bath according to the molar ratio of phenethylamine to p-toluenesulfonyl chloride of 1: 1-1.5, uniformly mixing, heating to room temperature, reacting for 0.5-2.0 h at the temperature, and adding phenethylamine, hydrochloric acid and methyl tert-butyl ether into the obtained reaction liquid according to the molar ratio of 1: 0.8-1.2: and (3) adding hydrochloric acid and methyl tert-butyl ether to 8.0-12.0, mixing and extracting, desolventizing the extracted organic phase, and distilling to obtain the phenethyl isothiocyanate.

According to a preferred embodiment of the invention, the molar ratio of phenethylamine, triethylamine and tetrahydrofuran is 1: 1.8-3.2: 8 to 12.

According to another preferred embodiment of the invention, the molar ratio of phenylethylamine to carbon disulphide is 1:1.2 to 1.8.

According to another preferred embodiment of the present invention, the molar ratio of phenethylamine to p-toluenesulfonyl chloride is 1:1.2 to 1.4.

According to another preferred embodiment of the invention, the molar ratio of phenethylamine, hydrochloric acid and methyl tert-butyl ether is 1: 0.9-1.1: 9.0 to 11.0.

According to another preferred embodiment of the present invention, the hydrochloric acid concentration in the mixture of phenethylamine, hydrochloric acid and methyl tert-butyl ether is 5 to 10% by weight.

According to another preferred embodiment of the present invention, the desolventizing step is to heat the washed combined organic phase at a temperature of 40 to 70 ℃.

According to another preferred embodiment of the present invention, the desolventized organic phase is distilled under a pressure of 0.2 to 0.3MPa and at a temperature of 110 to 130℃ to remove impurities contained therein, thereby obtaining phenethyl isothiocyanate with a content of 80.0 to 99.0% by weight.

The present invention will be described in more detail below.

The invention relates to a preparation method of phenylacetaldehyde.

In the presence of triethylamine base, firstly, phenylethylamine and carbon disulfide react in a tetrahydrofuran solvent to generate dithiocarbamate, and then, the dithiocarbamate is desulfurized by using a paratoluensulfonyl chloride desulfurizer, so that the phenethyl isothiocyanate is obtained. The preparation method has high conversion rate and convenient product transportation.

The preparation method comprises the following steps:

under the protection of nitrogen, phenylethylamine, triethylamine and tetrahydrofuran are mixed according to a molar ratio of 1: 1-4: 5-15 to obtain a mixture, and then in an ice water bath, mixing the mixture according to a molar ratio of phenylethylamine to carbon disulfide of 1: 1-2, dropwise adding carbon disulfide into the mixture by using a peristaltic pump, keeping the temperature at 0-5 ℃ for reaction, uniformly mixing, gradually heating to room temperature, and reacting at the temperature for 1-3 hours to obtain a reaction solution;

in this step, the reaction of phenethylamine and triethylamine with carbon disulfide needs to be carried out under the protection of nitrogen because air can have adverse effect on the reaction; the reaction needs to be carried out in an ice-water bath because the reaction is exothermic and the reaction temperature can be controlled by using the ice-water bath;

in the invention, when the dosage of the phenethylamine, the triethylamine and the carbon disulfide is in the range, if the dosage of the tetrahydrofuran is less than 5, the concentration of reactants is overlarge, and the reaction releases heat violently, so that the reaction is difficult to control and the danger of material flushing is easy to occur; if the consumption of the tetrahydrofuran is higher than 15, the reaction concentration is too low, the reaction time is prolonged, and the reaction energy consumption and the cost are increased; therefore, the amount of tetrahydrofuran is preferably 5 to 15, more preferably 8 to 12.

Similarly, when the amounts of phenethylamine, tetrahydrofuran and carbon disulfide are within the ranges, if the amount of triethylamine is less than 1, the reaction is incomplete and the product yield is reduced; if the amount of triethylamine is higher than 4, unnecessary preparation cost is increased; therefore, the amount of triethylamine is preferably 1 to 4, more preferably 1.8 to 3.2.

When the dosage of the phenethylamine, the triethylamine and the tetrahydrofuran is in the range, if the dosage of the carbon disulfide is lower than 1, the reaction is incomplete, and the yield of the product is reduced; if the amount of carbon dichloride is more than 2, unnecessary production costs are increased; accordingly, the amount of carbon disulfide is preferably 1 to 2, more preferably 1.2 to 1.8.

In the preparation step, the reaction time of phenylacetaldehyde, triethylamine and carbon disulfide is in a range of more than 1-3 h, which is unfavorable because the reaction time is shorter and incomplete, and the occurrence probability of side reactions is increased due to the longer time.

The peristaltic pump used in the present invention is a product generally used in the chemical technical field and sold in the market at present, for example, a peristaltic pump sold under the trade name of basic peristaltic pump BT600-02 by baoding constant flow pump limited.

Then, under an ice-water bath, dropwise adding p-toluenesulfonyl chloride into the reaction solution according to the molar ratio of phenethylamine to p-toluenesulfonyl chloride of 1: 1-1.5, uniformly mixing, heating to room temperature, reacting at the temperature for 0.5-2.0 h, and adding phenethylamine, hydrochloric acid and methyl tert-butyl ether into the obtained reaction solution according to the molar ratio of 1: 0.8-1.2: and (3) adding hydrochloric acid and methyl tert-butyl ether to 8.0-12.0, mixing and extracting, desolventizing the extracted organic phase, and distilling to obtain the phenethyl isothiocyanate.

The main role of p-toluenesulfonyl chloride in this step is to desulfurize the dithiocarbamate obtained from the above reaction to yield the phenethyl isothiocyanate of the present invention.

The main role of hydrochloric acid in this step is to quench the reaction.

The main role of methyl tert-butyl ether in this step is to extract the organic phase.

In the invention, if the molar ratio of phenethylamine to p-toluenesulfonyl chloride is more than 1:1, the desulfurization reaction is not completely carried out, and the product yield is reduced; if the molar ratio of phenethylamine to p-toluenesulfonyl chloride is less than 1:1.5, unnecessary preparation cost is increased; thus, the molar ratio of phenethylamine to p-toluenesulfonyl chloride was 1:1 to 1.5 are appropriate, preferably 1:1.2 to 1.4.

The mol ratio of phenethylamine to hydrochloric acid to methyl tert-butyl ether is 1: 0.8-1.2: 8.0 to 12.0, and it is not suitable if the amount thereof exceeds the above range. For example, in a mixture of phenethylamine, hydrochloric acid and methyl tert-butyl ether, a hydrochloric acid concentration exceeding the range of 5 to 10% by weight is disadvantageous in that too low a concentration results in too large an amount of waste water, and too high a concentration results in a drastic decrease in process safety. Preferably, the concentration of hydrochloric acid is 5-8% by weight.

Preferably, the molar ratio of phenethylamine, hydrochloric acid and methyl tert-butyl ether is 1: 0.9-1.1: 9.0 to 11.0.

Due to the product yield and energy consumption, the reaction time at room temperature after the dropwise addition of the p-toluenesulfonyl chloride is also unfavorable to exceed the range of 0.5 to 2 hours, preferably 0.5 to 1.5 hours.

The reaction solution for desulfurization contains impurities such as ammonium salts, and therefore, it is necessary to remove these impurities by extraction.

The extracted organic phase contains the methyl tert-butyl ether solvent and a small amount of washing liquid, and therefore it is necessary to remove these solvents and washing liquid for desolventizing. And the desolventizing is to heat the extracted organic phase at the temperature of 40-70 ℃ to remove the solvent contained in the extracted organic phase.

And distilling the desolventized organic phase under the conditions of pressure of 0.2-0.3 KPa and temperature of 110-130 ℃, and removing impurities contained in the organic phase to obtain phenethyl isothiocyanate with the content of 80-99% by weight.

The product prepared by the preparation method is analyzed and identified by the conventional infrared spectrum analysis and nuclear magnetic resonance spectroscopy, and the product is phenethyl isothiocyanate.

The content of phenethyl isothiocyanate in the product is determined to be 80.0-99.0% by weight by adopting a conventional gas chromatography analysis method.

[ advantageous effects ]

The invention has the beneficial effects that: the synthetic method of the invention uses phenylethylamine and carbon disulfide as raw materials, triethylamine is used as alkali to firstly generate dithiocarbamate, and then the phenethyl isothiocyanate is obtained by desulfurization of paratoluensulfonyl chloride. Compared with the prior art of phenethyl isothiocyanate, the synthesis method of the invention has the advantages of cheaper raw materials, easy transportation, high safety, relatively mild reaction conditions and high reaction yield, thus solving the problems of low conversion rate, low boiling point of the desulfurizer, high toxicity, extremely unsafe transportation, high product cost and the like in the prior art.

[ detailed description ] embodiments

The invention will be better understood from the following examples.