Method for preparing D, L-pantolactone through normal-pressure reduction

A technology of pantotolactone and pantoacid, which is applied in the field of preparation of D,L-pantotolactone, can solve problems such as high-risk processes and potential safety hazards, and achieve easy production operations, low production costs, and simple processes Effect

Pending Publication Date: 2020-07-24
内蒙古精晶生物科技有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The above method requires high-pressure hydrogenolysis, and the hydrogen pressur

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0027] Example 1

[0028] Add 74g (0.5mol) of 50% glyoxylic acid to a 500ml three-necked flask, cool the cooling device to 15℃, slowly add 53.12g (0.525mol) of triethylamine, add triethylamine, stir at 25℃ After 30 minutes, add 39.6g (0.55mol) of isobutyraldehyde, increase the temperature to 70°C and react for 6 hours, then lower the temperature to 15°C, slowly add 27g (0.5mol) potassium borohydride, after the addition is complete, react for 4 hours, and slowly add Add 70% sulfuric acid until the pH of the material liquid is 1.25, heat up to 87°C and react for 4 hours, cool the temperature to 15°C with the cooling device, adjust the pH of the material liquid to 7.5 with ammonia water, extract with dichloroethane, 300ml each time, combine the organic layers, The solvent was recovered by distillation, and under reduced pressure distillation was used to obtain 64 g of D,L-pantoate lactone, with a product yield of 98.5% and a purity of 99.16%.

Example Embodiment

[0029] Example 2

[0030] Add 92.5g (0.5 mole) of 40% glyoxylic acid to a 500ml three-necked flask, cool the cooling device to 25°C, slowly add 52.95g (0.725 mole) of diethylamine, after the addition of diethylamine, stir at 22°C After reacting for 30 minutes, 41.4g (0.575 mol) of isobutyraldehyde was added in flow, and the temperature was raised to 75°C to react for 7 hours, and the temperature was lowered to 20°C. 38g (1 mole) of sodium borohydride was slowly added. Add 80% sulfuric acid until the pH of the material liquid is 1.0, raise the temperature to 80°C and react for 3.5 hours, cool the temperature to 25°C with the cooling device, adjust the pH of the material liquid to 7.2 with sodium carbonate solution, extract with ethyl acetate, 280ml each time, combine the organic Layers, the solvent is recovered by distillation, and 63.5 g of D,L-pantoic acid lactone is obtained by distillation under reduced pressure. The product yield is 97.69% and the purity is 99.07%.

Example Embodiment

[0031] Example 3

[0032] Add 88.8g (0.6 mol) of 50% glyoxylic acid into a 500ml three-necked flask, cool the cooling device to 15°C, slowly add 30.54g (0.3 mol) of ethanolamine, after the addition of ethanolamine, stir and react at 30°C for 30 minutes. Add 43.2g (0.6 mol) of isobutyraldehyde, increase the temperature to 55°C and react for 7 hours, then lower the temperature to 15°C, slowly add 16.2g (0.3 mole) of potassium borohydride, after the addition is complete, react for 4 hours, slowly add 70% Sulfuric acid until the pH of the feed solution is 2, heated to 75°C for 4 hours, cooled to 15°C by the cooling device, adjusted the pH of the feed solution to 8 with ammonia water, extracted with ethyl acetate, 300ml each time, combined the organic layers, and distilled to recover the solvent. Under reduced pressure distillation, 76.44 g of D,L-pantoic acid lactone was obtained, the product yield was 98.0%, and the purity was 99.23%.

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Abstract

The invention discloses a method for preparing D, L-pantolactone through normal-pressure reduction, and belongs to the technical field of vitamin production. The method comprises the following steps:(1) adding organic alkali into glyoxylic acid at 15-35 DEG C; (2) adding isobutyraldehyde, and performing heating until aldehyde condensation reaction to generate 2-hydroxy-3-methyl-3-formylbutyric acid; (3) adding a reduction catalyst into the aldehyde condensation reaction solution, and carrying out reduction reaction to generate pantoic acid; (4) adding acid to carry out intermolecular dehydration cyclization to generate D, L-pantolactone; and (5) neutralizing, extracting, concentrating and distilling the feed liquid of D, L-pantolactone to obtain a D, L-pantolactone product. The method comprises the following steps: after 2-hydroxy-3-methyl-3-formylbutyric acid is generated through an aldehyde condensation reaction, carrying out a normal-temperature and normal-pressure reduction reaction by using a reduction catalyst to generate pantoic acid, so that high-risk processes such as highly toxic raw materials and high-pressure hydrogenolysis are avoided, heavy metal impurities are prevented from being introduced by using a hydrogenolysis catalyst, and operation is safe.

Description

technical field [0001] The invention relates to a preparation method of D, L-pantolactone, which belongs to the technical field of vitamin production. Background technique [0002] Calcium D-pantothenate generally refers to calcium D-cold acid, the drug name, mainly used in feed additives, food additives and various preparations such as tablets, capsules, oral liquids, and granules in the pharmaceutical industry. Calcium D-pantothenate can participate in basic metabolic functions in the body after entering animals or human bodies, participate in the synthesis of fatty acids, degrade and release a large amount of energy, promote the synthesis of antibodies that are resistant to pathogens, and promote animals or humans to respond to various nutrients. Absorption and utilization of substances. D, L-pantothenolactone is an important intermediate in the synthesis of calcium D-pantothenate, and can also be used in the synthesis of D-panthenol. [0003] In the prior art, the foll...

Claims

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Application Information

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IPC IPC(8): C07D307/33C07C51/367C07C59/105
CPCC07D307/33C07C51/367C07C59/105
Inventor 张玉锋李斌水米造吉何连顺李克赵聚波
Owner 内蒙古精晶生物科技有限公司
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