Method for preparing cysteamine hydrochloride by basic hydrolysis

A technology of cysteamine hydrochloride and alkali hydrolysis, which is applied in the direction of mercaptan preparation and organic chemistry, can solve the problems of complex operation, difficult discharge, low yield, etc., to reduce production costs, fully utilize resources, and rate-enhancing effect

Inactive Publication Date: 2008-07-23
CHONGQING UNIV
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  • Abstract
  • Description
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  • Application Information

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Problems solved by technology

(3) The reaction cycle is long (more than 50 hours, and only the second step of α-mercaptothiazoline hydrolysis takes 45 hours) and the product is easy to oxidize and change color, and it is not easy to discharge
Its shortcoming is (1) has used the poison hydrogen sulfide of suffocation that toxicity is more intense (2) productive rate is low, and total productive rate is 42.5% (3) the operation of 2-aminoethylsulfate and sodium hydroxide distillation step is complicated and The yield is not high (the yield of this step is 55%), the requirements are harsh and the operation is complicated when adding hydrogen sulfide

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  • Method for preparing cysteamine hydrochloride by basic hydrolysis
  • Method for preparing cysteamine hydrochloride by basic hydrolysis
  • Method for preparing cysteamine hydrochloride by basic hydrolysis

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Embodiment 1

[0026] The specific steps of a method for preparing cysteamine hydrochloride by alkali hydrolysis are as follows:

[0027] (1) Synthesis of 2-aminoethylsulfate

[0028] Under the ice-water bath condition, according to ethanolamine: the molar ratio of sulfuric acid is 1: 1.2, in the three-necked container, first add mass fraction and be 70% ethanolamine solution, then dropwise add mass fraction and be 50% sulfuric acid solution, stir and control while dripping. The temperature of the reaction solution was 10°C. After the dropwise addition was completed, the ice-water bath was removed, and the mixture was stirred at room temperature for 30 minutes. Then, the reaction solution was distilled under reduced pressure until anhydrous was distilled off. The final temperature of the reduced-pressure distillation was 145° C., and 2-aminoethyl sulfate was synthesized as a white solid.

[0029] (2) Synthesis of α-mercaptothiazoline

[0030] After the (1) step was completed, in the white...

Embodiment 2

[0036] A kind of method for preparing cysteamine hydrochloride by alkali hydrolysis is characterized in that:

[0037](1) ethanolamine: the mol ratio of sulfuric acid is 1: 1, and the massfraction of ethanolamine solution is 60%, and the massfraction of sulfuric acid solution is 50%, and dropwise temperature is 20 ℃, stirred at room temperature for 30 minutes, and distilled under reduced pressure The final temperature is 135°C;

[0038] (2) Adding a mass fraction of 20% sodium hydroxide solution, the molar ratio of sodium hydroxide: carbon disulfide: 2-aminoethyl sulfate is 1: 1: 1, and the temperature is raised to 45 ° C. After 2 hours of reaction, the temperature is raised to 55 ° C. ℃;

[0039] (3) The drying temperature is 60°C and the drying time is 4 hours;

[0040] (4) The mass fraction of sodium hydroxide solution is 20%, the mol ratio of α-mercaptothiazoline: sodium hydroxide is 1: 6, atmospheric pressure distillation 3 hours, pH is 3, rinses 4 times with dehydrated...

Embodiment 3

[0042] A kind of method for preparing cysteamine hydrochloride by alkali hydrolysis is characterized in that:

[0043] (1) ethanolamine: the mol ratio of sulfuric acid is 1: 1.2, and the massfraction of ethanolamine solution is 70%, and the massfraction of sulfuric acid solution is 50%, and dropwise temperature is 5 ℃, stirred at room temperature for 30 minutes, and distilled under reduced pressure The final temperature is 145°C;

[0044] (2) Adding a mass fraction of 20% potassium hydroxide solution, the molar ratio of potassium hydroxide: carbon disulfide: 2-aminoethyl sulfate is 1: 1.6: 1, and the temperature is raised to 45° C. After 2 hours of reaction, the temperature is raised to 55 ℃;

[0045] (3) The drying temperature is 60°C and the drying time is 4 hours;

[0046] (4) The mass fraction of sodium hydroxide solution is 20%, the mol ratio of α-mercaptothiazoline: sodium hydroxide is 1: 4, atmospheric pressure distillation 3 hours, pH is 2, wash 4 times with dehydrat...

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Abstract

The invention relates to a method using alkaline hydrolysis to prepare cysteamine hydrochloride, in particular to synthesizing cysteamine hydrochloride in alkali surroundings, which is characterized in that: ethanolamine solution and sulfate solution are used as raw material; 2- amino ethyl sulfate is firstly synthesized before made into ring in alkaline solution by 2-amino ethyl sulfate and carbon disulfide, thereby getting Alpha -mercaptothiazoline; alkaline hydrolysis is made upon Alpha -mercaptothiazoline to produce cysteamine hydrochloride. The preparation method for cysteamine hydrochloride by using alkaline hydrolysis has the advantages of simple method, short production period and low production cost. The recovery rate of synthesizing Alpha -mercaptothiazoline reaches more than 90%. The cysteamine hydrochloride can be widely applied in manufacturing anti-ulcer drugs such as ranitidine and cimetidine, manufacturing animal fodder additive, manufacturing cosmetic and hair wave-setting agent, manufacturing biochemical reagent and heavy metal ion complexion agent and manufacturing agent treating radiation syndrome and acute tetraethyl lead poisoning and in other areas.

Description

technical field [0001] The invention belongs to the technical field of preparation of heterocyclic series pharmaceutical intermediates, in particular to a method for synthesizing cysteamine hydrochloride in an alkaline environment. Background technique [0002] Cysteamine hydrochloride is an important chemical raw material and pharmaceutical intermediate. It can not only be used in the production of cosmetics and animal feed additives; it can also be used in the manufacture of anti-ulcer drugs such as ranitidine and cimetidine; it can also be used in the manufacture of biochemical reagents and complexing agents for heavy metal ions. Cysteamine can interact with certain enzymes in the body to stabilize it against radiation energy, and can be used for radiation syndrome and acute tetraethyl lead poisoning caused by X-rays or other radiation energy. Based on relevant domestic and foreign literature, the traditional process has been used for the synthesis of cysteamine hydrochl...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C323/25C07C319/02
Inventor 谭世语肖凤罗自萍邹小兵崔颖
Owner CHONGQING UNIV
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