阅读说明：本技术 一种光气合成氯甲酸正辛酯的方法 (Method for synthesizing n-octyl chloroformate by phosgene ) 是由 胡晓珊 杨云瑶 张敦河 刘亚龙 于 2020-12-08 设计创作，主要内容包括：本发明公开了一种光气合成氯甲酸正辛酯的方法,包括如下步骤：步骤一、将325重量份正戊醇加入反应容器；步骤二、将正戊醇降温至-15±1℃,然后逐渐通入420g重量份光气；其中,当光气通入量累计为0～195重量份时,控制反应容器内温度≤-10℃；当光气累计通入量为195～276重量份时,控制-10℃≤反应容器内温度≤-5℃；当光气累计通入量为276～325重量份时,反应容器内温度≤2℃；步骤三、当光气流量累计达到505重量份时,停止通光,将反应容器内的物料升温至20℃～25℃,并保温2小时；步骤四、保温完毕,通氮气除去过量的光气与氯化氢,得到合格的氯甲酸正庚酯产品。本发明流程简单,可以有效以减少碳酸二酯的生成,生产安全可靠且收率较高。(The invention discloses a method for synthesizing n-octyl chloroformate by phosgene, which comprises the following steps: step one, adding 325 parts by weight of n-amyl alcohol into a reaction vessel; step two, cooling the n-amyl alcohol to-15 +/-1 ℃, and then gradually introducing 420g of phosgene by weight; wherein when the cumulative introduction amount of phosgene is 0-195 parts by weight, the temperature in the reaction container is controlled to be less than or equal to-10 ℃; when the cumulative introduction amount of phosgene is 195-276 parts by weight, controlling the temperature in the reaction container to be less than or equal to-10 ℃ and less than or equal to-5 ℃; when the cumulative introducing amount of the phosgene is 276-325 parts by weight, the temperature in the reaction container is less than or equal to 2 ℃; step three, stopping light introduction when the accumulated phosgene flow reaches 505 parts by weight, heating the materials in the reaction container to 20-25 ℃, and preserving heat for 2 hours; and step four, after the heat preservation is finished, introducing nitrogen to remove excessive phosgene and hydrogen chloride, and obtaining the qualified chloroformic acid n-heptyl ester product. The method has simple process, can effectively reduce the generation of the carbonic diester, and has safe and reliable production and higher yield.)

1. The method for synthesizing n-octyl chloroformate by using phosgene is characterized by comprising the following steps of:

step one, adding 325 parts by weight of n-amyl alcohol into a reaction vessel;

step two, cooling the n-amyl alcohol to-15 +/-1 ℃, and then gradually introducing 420g of phosgene by weight; wherein when the cumulative introduction amount of phosgene is 0-195 parts by weight, the temperature in the reaction container is controlled to be less than or equal to-10 ℃; when the cumulative introduction amount of phosgene is 195-276 parts by weight, controlling the temperature in the reaction container to be less than or equal to-10 ℃ and less than or equal to-5 ℃; when the cumulative introduction amount of the phosgene is 276-325 parts by weight, controlling the temperature in the reaction container to be less than or equal to 2 ℃ below zero at the temperature of less than or equal to 5 ℃;

step three, stopping light introduction when the accumulated phosgene flow reaches 505 parts by weight, heating the materials in the reaction container to 20-25 ℃, and preserving heat for 2 hours;

and step four, after the heat preservation is finished, controlling the temperature of the materials in the reaction container to reach 15 +/-2 ℃, and introducing nitrogen to remove excessive phosgene and hydrogen chloride to obtain a qualified chloroformic acid n-heptyl ester product.

2. The method for phosgene synthesis of n-octyl chloroformate according to claim 1, further comprising a step five of absorbing the reaction off-gas with 10% liquid caustic.

3. The method for synthesizing n-octyl chloroformate by using phosgene, according to claim 1, wherein in the second step, when the cumulative amount of phosgene introduced is 0 to 195 parts by weight, the phosgene introduction speed is less than or equal to 30 parts by weight/h.

4. The method for synthesizing n-octyl chloroformate with phosgene according to claim 1, wherein in the second step, when the cumulative phosgene feed amount is not less than 195 parts by weight, the phosgene feed rate is 50 parts by weight/h.

5. The method for synthesizing n-octyl chloroformate by phosgene of claim 1, wherein the reaction vessel is a four-necked glass reaction bottle.

Technical Field

The invention relates to the field of chemistry, in particular to a method for synthesizing n-octyl chloroformate by phosgene.

Background

The n-octyl chloroformate is a chemical substance and is mainly used as a chemical solvent, an amino protective agent and chemical products for producing medicines, herbicides and the like. However, the carbonic acid diester which is easily produced as a by-product in the synthesis of n-octyl chloroformate at present causes low yield and purity of the product, so that improvement is needed.

Disclosure of Invention

The invention aims to provide a method for synthesizing n-octyl chloroformate by phosgene, which has simple process, can effectively reduce the generation of diester carbonate, and has safe and reliable production and higher yield.

In order to solve the problems, the technical scheme of the invention is as follows:

a method for synthesizing n-octyl chloroformate by phosgene comprises the following steps:

step one, adding 325 parts by weight of n-amyl alcohol into a reaction vessel;

step two, cooling the n-amyl alcohol to-15 +/-1 ℃, and then gradually introducing 420g of phosgene by weight; wherein when the cumulative introduction amount of phosgene is 0-195 parts by weight, the temperature in the reaction container is controlled to be less than or equal to-10 ℃; when the cumulative introduction amount of phosgene is 195-276 parts by weight, controlling the temperature in the reaction container to be less than or equal to-10 ℃ and less than or equal to-5 ℃; when the cumulative introduction amount of the phosgene is 276-325 parts by weight, controlling the temperature in the reaction container to be less than or equal to 2 ℃ below zero at the temperature of less than or equal to 5 ℃;

step three, stopping light introduction when the accumulated phosgene flow reaches 505 parts by weight, heating the materials in the reaction container to 20-25 ℃, and preserving heat for 2 hours;

and step four, after the heat preservation is finished, controlling the temperature of the materials in the reaction container to reach 15 +/-2 ℃, and introducing nitrogen to remove excessive phosgene and hydrogen chloride to obtain a qualified chloroformic acid n-heptyl ester product.

The further improvement also comprises a fifth step of absorbing the reaction tail gas by 10 percent liquid caustic soda.

In the second step, when the phosgene introducing amount is accumulated to be 0-195 parts by weight, the phosgene introducing speed is less than or equal to 30 parts by weight/h.

In the second step, when the cumulative phosgene feeding amount is not less than 195 parts by weight, the phosgene feeding speed is 50 parts by weight/h.

In a further improvement, the reaction vessel is a four-mouth glass reaction bottle.

The invention has the advantages that:

the method has simple process, can effectively reduce the generation of the carbonic diester, and has safe and reliable production and higher yield.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

A method for synthesizing n-octyl chloroformate by phosgene comprises the following steps:

first, experimental equipment and reagent

A 1000ml four-mouth glass reaction bottle, a tetrafluoro stirring and stirring speed regulator, a +/-50 ℃ thermometer, a low-temperature constant-temperature reaction bath, an LZB glass rotameter and a tail gas absorption bottle; n-octanol, 10% caustic soda.

Synthesis method

Reaction type

CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₂OH+COCl₂→CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₂OCOCl+HCl

1. And (3) adding 325g of n-amyl alcohol into a 1000ml four-mouth reaction bottle, adjusting the low-temperature constant-temperature reaction bath under stirring, and reducing the temperature of the materials in the reaction bottle to about-15 ℃.

2. When the temperature of the materials in the reaction bottle is reduced to about-15 ℃, 420g of phosgene (broken by hundred percent) is introduced through a flowmeter.

The control table of phosgene cumulative flow and light-passing temperature is as follows

Cumulative flow of phosgene	Light passing temperature control
		0～195g	≤-10℃
195g～276g	≤-5℃
		276g～325g	≤2℃

3. The reaction temperature rises faster in the early stage of light-transmitting, and the light-transmitting temperature is controlled not to exceed minus 10 ℃ by adjusting the phosgene flow (the early stage is generally less than 30g/h) so as to reduce the generation of carbonic diester. Along with the accumulative absorption of phosgene, the material temperature is gradually reduced, the light flux can be gradually increased to 50g/h, the flux is too large, and phosgene is not easy to be completely absorbed and has more loss. The temperature rise should be kept constant and slow in the light-transmitting process.

4. Controlling the molar ratio of n-amyl alcohol to phosgene to be 1: 1.7.

5. When the phosgene flow is accumulated to 325g, stopping introducing light, slowly heating the material to 20-25 ℃ at a constant speed, and preserving heat for 2 hours.

6. After the heat preservation is finished, nitrogen is introduced at the temperature of 15 +/-2 ℃ to remove excess phosgene and hydrogen chloride, so that a qualified n-octyl chloroformate product with the content of 98.5-99.0 percent (analyzed by gas chromatography) is obtained, and the yield is more than 97 percent.

7. The reaction tail gas is absorbed by 10 percent liquid caustic soda.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.