CN102229550A

CN102229550A - Method for preparing 3-mercaptopropionic acid

Info

Publication number: CN102229550A
Application number: CN2011101356734A
Authority: CN
Inventors: 薄宪明; 贺芬霞; 张婧
Original assignee: YUANPING TONGLI CHEMICAL CO Ltd
Current assignee: YUANPING TONGLI CHEMICAL CO Ltd
Priority date: 2011-05-25
Filing date: 2011-05-25
Publication date: 2011-11-02

Abstract

The invention discloses a method for preparing 3-mercaptopropionic acid, comprising the following steps of: (1), after mixing thiourea and hydrochloric acid, stirring; (2), dropping acrylic acid; keeping temperature at 80-90 degrees centigrade; and keeping the reaction for 1-7 h; (3), adding sodium hydroxide solution; hydrolyzing; generating sulphur sodium propionate and urea; and (4), acidizing by adding hydrochloric acid; preparing solution containing 3-mercaptopropionic acid; and, after extracting through an organic solvent, decompressing and distilling to obtain the 3-mercaptopropionic acid. Reaction liquid contains a few by-products. The extraction process is easily carried out. The product is good in colour and high in content. After being extracted, waste liquid can be separated and recycled by simply distilling and filtering. Residual liquid can be added to new waste liquid to be further treated. The zero emission of the three wastes (waste gas, waste water and industrial residue) can be basically realized.

Description

A kind of preparation method of 3-thiohydracrylic acid

Technical field

The present invention relates to a kind of preparation method of 3-thiohydracrylic acid, specifically is a kind of method for preparing the 3-thiohydracrylic acid with vinylformic acid.

Background technology

The 3-thiohydracrylic acid is medical chlomezanone intermediate, also as polyvinyl chloride (PVC) stabilizer, oxidation inhibitor, catalyzer and biochemical reagents.The method of existing synthetic 3-thiohydracrylic acid mainly contains three kinds: vinyl cyanide---thiocarbamide method, vinyl cyanide---Sodium sulfhydrate or thio sulfate method, vinylformic acid---hydrogen sulfide high pressure synthesis method.

Vinyl cyanide---thiocarbamide method is with thiocarbamide and hydrochloric acid stirring reaction, cools off, drips vinyl cyanide then, is incubated 3 hours down at 100-115 ℃.Be cooled to again below 40 ℃, drip liquid sodium hydroxide, be warming up to 100-115 ℃ of reaction 4 hours again.After the ammonia excretion cooling, add hcl acidifying again, make the aqueous solution that contains the 3-thiohydracrylic acid.The shortcoming of this method is the vinyl cyanide severe toxicity, and the ammonia of generation need absorb with acid, causes ammonia leakage, contaminate environment easily.

Vinyl cyanide---Sodium sulfhydrate or thio sulfate method, this method is with aqueous sodium hydroxide solution, Sodium sulfhydrate and sodium polysulphide mixed solution (perhaps directly using Sulfothiorine), drip vinyl cyanide at 20-70 ℃, insulation generates the mixed solution of multiple intermediate, add hydrochloric acid then and carry out acidifying, add zinc powder again and reduce, obtain containing the solution of 3-thiohydracrylic acid.The shortcoming of this method is that impurity is difficult to handle more in vinyl cyanide severe toxicity, the reaction solution, and simultaneously excessive Sodium sulfhydrate or Sulfothiorine have hydrogen sulfide to produce in acidization, promptly use alkali to absorb, and also are easy to leak, and pollute.

Vinylformic acid---hydrogen sulfide high pressure synthesis method, it mainly is the method for carrying out addition at acrylate and hydrogen sulfide, as catalyzer, carry out the addition reaction of hydrogen sulfide and acrylate with the functionalized solid carrier of guanidine basic functionality, the method for synthetic 3-mercaptopropionic acid ester.Therefore and be not suitable for vinylformic acid and synthesize the 3-thiohydracrylic acid with hydrogen sulfide this method is synthetic with autoclave, because vinylformic acid has the deep-etching effect to autoclave.

Summary of the invention

The objective of the invention is to solve reactant raffinate and the reluctant problem of by product that exists among the existing 3-thiohydracrylic acid preparation method, a kind of preparation method of 3-thiohydracrylic acid is provided.

For achieving the above object, the technical solution used in the present invention is: a kind of preparation method of 3-thiohydracrylic acid carries out according to following steps: stir after with thiocarbamide and mixed in hydrochloric acid (1); (2) be added dropwise to vinylformic acid and maintain the temperature at 80-90 ℃, kept reaction times 1-7 hour; (3) the hydro-oxidation sodium solution is hydrolyzed, and generates thiohydracrylic acid sodium and urea; (4) add hcl acidifying, make the solution that contains the 3-thiohydracrylic acid; (5) solution in the previous step is behind organic solvent extraction, and underpressure distillation steams product 3-thiohydracrylic acid;

The add-on of above-mentioned each reactant with molar ratio computing is:

Hydrochloric acid: thiocarbamide=1.0-1.5:1;

Vinylformic acid: thiocarbamide=1.1-1.5:1;

Sodium hydroxide: thiocarbamide=2.1-3.0:1;

Hydrochloric acid: thiocarbamide=1.2-1.5:1.

As a kind of optimized technical scheme, in the step (1), thiocarbamide and hydrochloric acid stirred 0.5-2.0 hour at 40-90 ℃.

As a kind of optimized technical scheme: in the step (2), the temperature of dropwise addition of acrylic acid is 60-90 ℃, and the dropping time is 0.5-2.0 hour.

As a kind of optimized technical scheme, step (3), the temperature of reaction behind the hydro-oxidation sodium solution are 90-110 ℃, and the reaction times is 0.5-3 hour.

As a kind of optimized technical scheme, the temperature that step (4) adds hcl acidifying is 20-60 ℃, and acidificatoin time is 0.2-1 hour.

As a kind of optimized technical scheme, the organic solvent described in the step (5) is a kind of or any two kinds in benzene, dimethylbenzene, ethyl acetate, tetracol phenixin, the methylene dichloride.

Method provided by the invention is compared with method in the past, and the by product in the reaction solution is few, extraction easily, the good content height of product color.Unreacted vinylformic acid and thiocarbamide in the waste liquid of extraction back, sodium-chlor, urea and water that reaction generates can Separation and Recovery by simple distillation and filtration.Thiocarbamide and urea can be used for synthetic urea-formaldehyde resin, and sodium-chlor can be used as industrial use, can continue to use after vinylformic acid reclaims, and water can be used for boiler feed water.Raffinate can join in the new waste liquid and further handle, and can realize zero emission substantially.

Embodiment

Embodiment 1

1mol thiocarbamide and 1.0mol hydrochloric acid stirred 0.5 hour at 40 ℃; 60 ℃ of dropwise addition of acrylic acid 1.1mol, temperature, the dropping time is 0.5 hour, and the temperature of keeping reaction is 80 ℃, and the time of keeping reaction is 1 hour; The temperature of reaction that adds behind the 2.1mol sodium hydroxide is 90 ℃, and the reaction times is 0.5 hour; The temperature that adds 1.2 hcl acidifyings is 20 ℃, and acidificatoin time is 0.2 hour, obtains the solution of 3-thiohydracrylic acid; With the benzene extraction, underpressure distillation steams product 3-thiohydracrylic acid at last.

Embodiment 2

1mol thiocarbamide and 1.5mol hydrochloric acid stirred 2.0 hours at 90 ℃; 90 ℃ of dropwise addition of acrylic acid 1.5mol, temperature, the dropping time is 2.0 hours, and the temperature of keeping reaction is 90 ℃, and the time of keeping reaction is 7 hours; The temperature of reaction that adds behind the 3.0mol sodium hydroxide is 110 ℃, and the reaction times is 3 hours; The temperature that adds the 1.5mol hcl acidifying is 60 ℃, and acidificatoin time is 1 hour, obtains the solution of 3-thiohydracrylic acid; Use benzene and xylene extraction at last, underpressure distillation steams product 3-thiohydracrylic acid.

Embodiment 3

1mol thiocarbamide and 1.2mol hydrochloric acid stirred 1.2 hours at 70 ℃; 75 ℃ of dropwise addition of acrylic acid 1.3mol, temperature, the dropping time is 1.5 hours, and the temperature of keeping reaction is 85 ℃, and the time of keeping reaction is 4 hours; The temperature of reaction that adds behind the 2.5mol sodium hydroxide is 100 ℃, and the reaction times is 1.5 hours; The temperature that adds the 1.3mol hcl acidifying is 20-60 ℃, and acidificatoin time is 0.6 hour, obtains the solution of 3-thiohydracrylic acid; Use ethyl acetate extraction at last, underpressure distillation steams product 3-thiohydracrylic acid.

Embodiment 4

1mol thiocarbamide and 1.0mol hydrochloric acid stirred 0.5 hour at 90 ℃; 60 ℃ of dropwise addition of acrylic acid 1.5mol, temperature, the dropping time is 2.0 hours, and the temperature of keeping reaction is 80 ℃, and the time of keeping reaction is 7 hours; The temperature of reaction that adds behind the 3.0mol sodium hydroxide is 90 ℃, and the reaction times is 3 hours; The temperature that adds the 1.2mol hcl acidifying is 60 ℃, and acidificatoin time is 0.2 hour, obtains the solution of 3-thiohydracrylic acid; Use ethyl acetate and carbon tetrachloride extraction at last, underpressure distillation steams product 3-thiohydracrylic acid.

Embodiment 5

1mol thiocarbamide and 1.5mol hydrochloric acid stirred 1.5 hours at 60 ℃; 80 ℃ of dropwise addition of acrylic acid 1.2mol, temperature, the dropping time is 1.5 hours, and the temperature of keeping reaction is 85 ℃, and the time of keeping reaction is 6 hours; The temperature of reaction that adds behind the 2.5mol sodium hydroxide is 95 ℃, and the reaction times is 2 hours; The temperature that adds 1.4 hcl acidifyings is 30 ℃, and acidificatoin time is 0.5 hour, obtains the solution of 3-thiohydracrylic acid; Use dichloromethane extraction at last, underpressure distillation steams product 3-thiohydracrylic acid.

Claims

1. the preparation method of a 3-thiohydracrylic acid is characterized in that described method carries out according to following steps: stir after with thiocarbamide and mixed in hydrochloric acid (1); (2) be added dropwise to vinylformic acid and maintain the temperature at 80-90 ℃, kept reaction times 1-7 hour; (3) the hydro-oxidation sodium solution is hydrolyzed, and generates thiohydracrylic acid sodium and urea; (4) add hcl acidifying, make the solution that contains the 3-thiohydracrylic acid; (5) solution in the previous step is behind organic solvent extraction, and underpressure distillation steams product 3-thiohydracrylic acid;

The add-on of above-mentioned each reactant with molar ratio computing is:

In step poly-(1), hydrochloric acid: thiocarbamide=1.0-1.5:1;

In step poly-(2), vinylformic acid: thiocarbamide=1.1-1.5:1;

In step poly-(3), sodium hydroxide: thiocarbamide=2.1-3.0:1;

In step poly-(4), hydrochloric acid: thiocarbamide=1.2-1.5:1.

2. the preparation method of a kind of 3-thiohydracrylic acid according to claim 1 is characterized in that: in the step (1), thiocarbamide and hydrochloric acid stirred 0.5-2.0 hour at 40-90 ℃.

3. the preparation method of a kind of 3-thiohydracrylic acid according to claim 1 is characterized in that: in the step (2), the temperature of dropwise addition of acrylic acid is 60-90 ℃, and the dropping time is 0.5-2.0 hour.

4. the preparation method of a kind of 3-thiohydracrylic acid according to claim 1 is characterized in that: in the step (3), the temperature of reaction behind the hydro-oxidation sodium solution is 90-110 ℃, and the reaction times is 0.5-3 hour.

5. the preparation method of a kind of 3-thiohydracrylic acid according to claim 1 is characterized in that: in the step (4), the temperature that adds hcl acidifying is 20-60 ℃, and acidificatoin time is 0.2-1 hour.

6. the preparation method of a kind of 3-thiohydracrylic acid according to claim 1, the organic solvent described in the step (5) is a kind of or any two kinds in benzene, dimethylbenzene, ethyl acetate, tetracol phenixin, the methylene dichloride.