Process for preparing isooctyl thioglycolate

Abstract

The invention relates to a process for preparing isooctyl thioglycolate. The process provided by the invention is characterized in that chloroacetic acid is taken as a raw material, the chloroacetic acid and isooctanol are subjected to an esterification reaction in the presence of a catalyst to synthesize isooctyl chloroacetate; then the isooctyl chloroacetate and sodium thiosulfate are reacted to form a Bunte salt and the Bunte salt is subjected to acidolysis and reduction to obtain a rough product of the isooctyl thioglycolate; and the rough product is rectified to obtain the finished product of the isooctyl thioglycolate. The process for preparing the isooctyl thioglycolate has higher yield; the isopropanol is used as the solvent. the experiment shows that the yield can be about 65% and the yield is improved by about 5% compared with the yield obtained by taking methanol, ethanol and the like as the solvent; and the time for recycling the isopropanol is only about 2.5 hours and the time is shortened by about 2 hours compared with the time for recycling the methanol, ethanol and the like so that the relative energy consumption is greatly reduced.

Description

technical field

[0001] The invention relates to a process for preparing an intermediate of a PVC heat stabilizer, in particular to a process for preparing isooctyl thioglycolate. Background technique

[0002] Isooctyl mercaptoacetate is an intermediate for synthesizing high-efficiency and low-toxic organotin PVC heat stabilizers, and can also be used as a chain-blocking agent for PVC resin polymerization and a catalyst for the synthesis of bisphenol A.

[0003] Synthetic isooctyl thioglycolate mainly contains two operational routes in the prior art: the one, synthesize thioglycolic acid earlier, carry out the direct esterification method of esterification with isooctyl alcohol then; Another route is to synthesize isooctyl chloroacetate earlier, Then carry out sulfhydrylation. For the former route, through experiments, it is believed that there are two problems; one is that the cost of thioglycolic acid synthesized is relatively high, and the ester reaction is difficult to a...

Examples

Embodiment 1

[0027] Example 1. A kind of preparation technology of isooctyl thioglycolate, its step is as follows:

[0028] (1) Esterification reaction: first add chloroacetic acid to the reaction kettle, then add isooctyl alcohol and concentrated sulfuric acid as a catalyst, and perform esterification reaction while distilling water under reduced pressure. After the reaction, wash with sodium carbonate and saline solution. Then wash with water, wash the waste water to the waste water collection tank, and the esterification product to the esterification storage tank; open the valve at the bottom of the water separator, pour the water into the waste water tank, and put the remaining ester-alcohol mixture into the next batch; among them: chloroacetic acid , The weight ratio of isooctyl alcohol to catalyst is 800:1000:8;

[0029] (2) Mercaptolation reaction: Measure the esterified product in the esterified product storage tank into the esterified product metering tank and put it into the rea...

Embodiment 2

[0032] Example 2. A kind of preparation technology of isooctyl thioglycolate, its step is as follows:

[0033] (1) Esterification reaction: first add chloroacetic acid to the reaction kettle, then add isooctyl alcohol and concentrated sulfuric acid as a catalyst, and perform esterification reaction while distilling water under reduced pressure. After the reaction, wash with sodium carbonate and saline solution. Then wash with water, wash the waste water to the waste water collection tank, and the esterification product to the esterification storage tank; open the valve at the bottom of the water separator, pour the water into the waste water tank, and put the remaining ester-alcohol mixture into the next batch; among them: chloroacetic acid , the weight ratio of isooctyl alcohol and catalyst is 800: 1150: 10;

[0034] (2) Mercaptolation reaction: Measure the esterified product in the esterified product storage tank into the esterified product metering tank and put it into the...

Embodiment 3

[0037] Example 3. A kind of preparation technology of isooctyl thioglycolate, its step is as follows:

[0038] (1) Esterification reaction: first add chloroacetic acid to the reaction kettle, then add isooctyl alcohol and concentrated sulfuric acid as a catalyst, and perform esterification reaction while distilling water under reduced pressure. After the reaction, wash with sodium carbonate and saline solution. Then wash with water, wash the waste water to the waste water collection tank, and the esterification product to the esterification storage tank; open the valve at the bottom of the water separator, pour the water into the waste water tank, and put the remaining ester-alcohol mixture into the next batch; among them: chloroacetic acid , The weight ratio of isooctyl alcohol to catalyst is 800:1090:9;

[0039](2) Mercaptolation reaction: Measure the esterified product in the esterified product storage tank into the esterified product metering tank and put it into the reac...

technical field

[0001] The invention relates to a process for preparing an intermediate of a PVC heat stabilizer, in particular to a process for preparing isooctyl thioglycolate. Background technique

[0002] Isooctyl mercaptoacetate is an intermediate for synthesizing high-efficiency and low-toxic organotin PVC heat stabilizers, and can also be used as a chain-blocking agent for PVC resin polymerization and a catalyst for the synthesis of bisphenol A.

[0003] Synthetic isooctyl thioglycolate mainly contains two operational routes in the prior art: the one, synthesize thioglycolic acid earlier, carry out the direct esterification method of esterification with isooctyl alcohol then; Another route is to synthesize isooctyl chloroacetate earlier, Then carry out sulfhydrylation. For the former route, through experiments, it is believed that there are two problems; one is that the cost of thioglycolic acid synthesized is relatively high, and the ester reaction is difficult to a...

Examples

Embodiment 1

[0027] Example 1. A kind of preparation technology of isooctyl thioglycolate, its step is as follows:

[0028] (1) Esterification reaction: first add chloroacetic acid to the reaction kettle, then add isooctyl alcohol and concentrated sulfuric acid as a catalyst, and perform esterification reaction while distilling water under reduced pressure. After the reaction, wash with sodium carbonate and saline solution. Then wash with water, wash the waste water to the waste water collection tank, and the esterification product to the esterification storage tank; open the valve at the bottom of the water separator, pour the water into the waste water tank, and put the remaining ester-alcohol mixture into the next batch; among them: chloroacetic acid , The weight ratio of isooctyl alcohol to catalyst is 800:1000:8;

[0029] (2) Mercaptolation reaction: Measure the esterified product in the esterified product storage tank into the esterified product metering tank and put it into the rea...

Embodiment 2

[0032] Example 2. A kind of preparation technology of isooctyl thioglycolate, its step is as follows:

[0033] (1) Esterification reaction: first add chloroacetic acid to the reaction kettle, then add isooctyl alcohol and concentrated sulfuric acid as a catalyst, and perform esterification reaction while distilling water under reduced pressure. After the reaction, wash with sodium carbonate and saline solution. Then wash with water, wash the waste water to the waste water collection tank, and the esterification product to the esterification storage tank; open the valve at the bottom of the water separator, pour the water into the waste water tank, and put the remaining ester-alcohol mixture into the next batch; among them: chloroacetic acid , the weight ratio of isooctyl alcohol and catalyst is 800: 1150: 10;

[0034] (2) Mercaptolation reaction: Measure the esterified product in the esterified product storage tank into the esterified product metering tank and put it into the...

Embodiment 3

[0037] Example 3. A kind of preparation technology of isooctyl thioglycolate, its step is as follows:

[0038] (1) Esterification reaction: first add chloroacetic acid to the reaction kettle, then add isooctyl alcohol and concentrated sulfuric acid as a catalyst, and perform esterification reaction while distilling water under reduced pressure. After the reaction, wash with sodium carbonate and saline solution. Then wash with water, wash the waste water to the waste water collection tank, and the esterification product to the esterification storage tank; open the valve at the bottom of the water separator, pour the water into the waste water tank, and put the remaining ester-alcohol mixture into the next batch; among them: chloroacetic acid , The weight ratio of isooctyl alcohol to catalyst is 800:1090:9;

[0039](2) Mercaptolation reaction: Measure the esterified product in the esterified product storage tank into the esterified product metering tank and put it into the reac...

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