Method for preparing vitamin B1 intermediate (pyrimidine)

A technology for vitamins and intermediates, which is applied in the field of preparing vitamin B1 intermediates, can solve the problems of solute and solvent loss, high odor, low combined yield of thiothiamine, etc., so as to reduce the dissolution loss of solvents and simplify the production operation process. , The effect of reducing the amount of solvent recovery

Inactive Publication Date: 2015-09-16
江苏兄弟维生素有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Wherein thiothiamine (2-methyl-4,5-diaminopyrimidine) is the important intermediate of this method synthetic vitamin B1, and the method for above-mentioned preparation 2-methyl-4,5-diaminopyrimidine exists following Disadvantages: During the preparation process, it is necessary to filter and dry, that is, to separate the solid from the liquid. On the one hand, the separation operation is troublesome and the process is labor-intensive; on the other hand, it is easy to cause the loss of solute and solvent, and the combined yield from enamine to thiothiamine It is relatively low, and produces a lot of solid waste, which has a strong smell and high energy consumption, which is not conducive to the protection of the environment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Use 140g of liquid sodium methylate to dissociate 70g of diethyl ether hydrochloride (mass ratio 2:1), and filter the solution into a reactor to add 105g of α-(o-chloroaniline) methine-β-formamidopropionitrile (enamine), Collect alcohol under the conditions of -0.06~-0.1MPa vacuum, temperature 70~80 degrees, and cyclization reaction for 2~4 hours;

[0016] After the water vapor is generated by the water vapor generator, it is passed into the reaction liquid, and the water vapor distillation is carried out under the condition of 100-110 degrees until all the o-chloroaniline in the solution is evaporated;

[0017] After steaming, add 150g of liquid caustic soda NaOH, add 300g of methanol after hydrolyzing at 100-130 degrees for 2 hours, then add 40g of carbon disulfide and react with ammonium salt at 30-50 degrees for 1-3 hours, then add γ-chloro-γ- 70g of acetylpropanol was subjected to condensation reaction at 40-60°C for 2-5 hours and then filtered to obtain crude thio...

Embodiment 2

[0021] Use 140g of liquid sodium methylate to dissociate 70g of diethyl ether hydrochloride (mass ratio 2:1), and filter the solution into the reactor

[0022] 105 g of α-(o-chloroaniline) methine-β-formamidopropionitrile (enamine) was added to the mixture, and the alcohol was collected under the vacuum of -0.06~-0.1MPa and the temperature was 70~80 degrees, and the ring closure reaction was 2 ~4 hours;

[0023] Then add 400g of water and carry out steam distillation under the condition of 110~120 degrees, all the o-chloroaniline in the solution is steamed out;

[0024] After steaming, add 150g of liquid caustic soda NaOH, add 300g of methanol after hydrolyzing at 100-130 degrees for 2 hours, then add 40g of carbon disulfide and react with ammonium salt at 30-50 degrees for 1-3 hours, then add γ-chloro-γ- 70g of acetylpropanol was subjected to condensation reaction at 40-60°C for 2-5 hours and then filtered to obtain crude thiothiamine;

[0025] Dissolve the crude thiothiami...

Embodiment 3

[0028] Use 140g of liquid sodium methylate to dissociate 70g of diethyl ether hydrochloride (mass ratio 2:1), and filter the solution into a reactor to add 105g of α-(o-chloroaniline) methine-β-formamidopropionitrile (enamine), Collect alcohol under the conditions of -0.06~-0.1MPa vacuum, temperature 70~80 degrees, and cyclization reaction for 2~4 hours;

[0029] Then add 400g of water, control the temperature and carry out steam distillation under the condition of 120-130 degrees, and all the o-chloroaniline in the solution will be steamed out;

[0030] After steaming, add 150g of liquid caustic soda NaOH, add 300g of methanol after hydrolyzing at 100-130 degrees for 2 hours, then add 40g of carbon disulfide and react with ammonium salt at 30-50 degrees for 1-3 hours, then add γ-chloro-γ- 70g of acetylpropanol was subjected to condensation reaction at 40-60°C for 2-5 hours and then filtered to obtain crude thiothiamine;

[0031] The obtained crude product was dissolved with ...

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PUM

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Abstract

The invention discloses a method for preparing a vitamin B1 intermediate (pyrimidine). The method comprises the following steps: directly carrying out water vapor distillation to recover o-chloroaniline, hydrolyzing, adding methanol, and properly controlling the aminopyrimidine concentration and the methanol concentration to obtain the intermediate thiothiamine used in a next process. The method has the advantages of simple process operation, high combined yield, environmental protection and energy saving.

Description

technical field [0001] The invention relates to the technical field of vitamin production and processing, in particular to a method for preparing vitamin B1 intermediates. Background technique [0002] Vitamin B1, whose biochemical name is thiamine, is a water-soluble vitamin. At present, the synthesis technology of vitamin B1 at home and abroad is relatively mature, and the synthesis routes mainly include the route of acrylonitrile acetylpyrimidine, the route of acrylonitrile formyl pyrimidine and the route of malononitrile. [0003] In China, the acrylonitrile formyl pyrimidine route is generally used to synthesize vitamin B1. This method mainly includes aminopropionitrile, sodium substitution, enamine, pyrimidine, chlorate, ether hydrochloride, thiothiamine, thiothiamine oxidation, sulfuric acid nitric acid, and sulfuric acid. Amine neutralization, and thiamine hydrochloride and other processes. Wherein thiothiamine (2-methyl-4,5-diaminopyrimidine) is the important inte...

Claims

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Application Information

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IPC IPC(8): C07D417/06
CPCC07D417/06
Inventor 李来成沈银元陈英明崔胜凯
Owner 江苏兄弟维生素有限公司
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