One-pot preparation method of vitamin B6

A vitamin and methyl technology, applied in the field of medicine and biochemical industry, can solve the problems of difficult decolorization, high price, heavy product coloring, etc., and achieve the effects of short process flow, high selectivity and simple operation.

Active Publication Date: 2013-04-24
XINFA PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] U.S. Patent US3227721 mentions that 2-methyl-3-hydroxy-pyridine-4,5-dicarboxylate uses lithium tetrahydrogen aluminum as a reducing agent, and there is a large amount of lithium tetrahydrogen, which is expensive, high in cost, and safe Large hidden dangers, inconvenient operation and other disadvantages
In addition, currently existing VB 6 The preparation process, including addition reaction, aromatization, hydrolysis, etc., has relatively long production cycle, produces a lot of three wastes, serious environmental pollution, and the product is heavily colored and difficult to decolorize.

Method used

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  • One-pot preparation method of vitamin B6
  • One-pot preparation method of vitamin B6
  • One-pot preparation method of vitamin B6

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Add 144g of dimethyl maleate and 127g of 4-methyl-5-ethoxy oxazole to a dry 500mL four-neck flask, heat up to 80°C and react for 15 hours to obtain 2-methyl-3-hydroxy-pyridine Dimethyl-4,5-dicarboxylate 221.5g, purity 98.5% (GC), yield 97%, the product was confirmed by GC-MS analysis, see figure 1 and figure 2 .

[0035] Put 56g of 2-methyl-3-hydroxy-pyridine-4,5-dicarboxylate into a 500mL autoclave, 202g of methanol as a solvent, 6g of activated T-1 Raney nickel catalyst, nitrogen replacement three times, Replace with hydrogen three times, then add hydrogen for reduction, continue to flow hydrogen during the reaction process, keep the reaction pressure 2.0MPa, temperature 65°C, hydrogenation reaction for 6 hours, lower the temperature, filter to remove the catalyst; pass hydrogen chloride gas until saturated to form a salt, and recover methanol under reduced pressure. Then add 65mL of ethanol, take a water bath at 70°C, hold time for 30 minutes, slowly cool down to ...

Embodiment 2

[0037] Add 144g of dimethyl maleate and 127g of 4-methyl-5-ethoxy oxazole to a dry 500mL four-neck flask, heat up to 90°C and react for 13 hours to obtain 2-methyl-3-hydroxy-pyridine Dimethyl-4,5-dicarboxylate 219g, purity 98.2% (GC), yield 95.6%.

[0038]Put 56g of 2-methyl-3-hydroxy-pyridine-4,5-dicarboxylate into a 500mL autoclave, 202g of methanol as solvent, 8g of activated T-1 type Raney nickel catalyst, nitrogen replacement three times, The hydrogen was replaced three times, and then hydrogenated for reduction. During the reaction process, the hydrogen gas was continuously passed, and the reaction pressure was kept at 2.5Mpa, and the temperature was 68°C. The hydrogenation reaction was carried out for 5 hours, and the temperature was lowered. Then add 65mL of ethanol, take a water bath at 70°C, keep time for 30min, then slowly cool down to 15-20°C, and filter with suction for 30min to crystallize. 90.1%.

Embodiment 3

[0040] Add 158g of dimethyl maleate and 127g of 4-methyl-5-ethoxy oxazole to a dry 500mL four-neck flask, heat up to 100°C and react for 11 hours to obtain 2-methyl-3-hydroxy-pyridine Dimethyl-4,5-dicarboxylate 222g, purity 98.9% (GC), yield 97.6%.

[0041] Put 56g of 2-methyl-3-hydroxy-pyridine-4,5-dicarboxylate into a 500mL autoclave, 202g of methanol as solvent, 10g of activated T-1 type Raney nickel catalyst, nitrogen replacement three times, The hydrogen was replaced three times, and then hydrogenated for reduction. During the reaction process, the hydrogen was continuously passed, and the reaction pressure was kept at 3.0Mpa, and the temperature was 68°C. The hydrogenation reaction was carried out for 5 hours, and the temperature was lowered. Then add 65mL of ethanol, take a water bath at 70°C, keep timed for 30 minutes, then slowly cool down to 15-20°C, and filter with suction for 30 minutes to crystallize. The rate is 91.2%.

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Abstract

The invention relates to a new one-pot preparation method of vitamin B6. The method includes that 5-ethoxy-4-methyloxazole which is a key intermediate of vitamin B6 and dimethyl maleate or diethyl maleate are subjected to Diels-Alder addition reaction and aromatization to further form pyridine rings, and then the pyridine rings undergo hydrogenation to be catalytically reduced to vitamin B6. The one-pot method is adopted, so that the intermediates can directly react without separation. The period of technological processes is shortened, and the one-pot preparation method of vitamin B6 is simple in operation, environment-friendly and low in cost. Moreover, the selectivity, the yield and the purity of the product are high, and the method is more suitable for being used for large-scale industrial production.

Description

technical field [0001] The invention relates to a one-pot method for preparing vitamin B 6 The method belongs to the field of pharmaceutical biochemical technology. Background technique [0002] Vitamin B 6 (Vitamin B 6 , referred to as VB 6 ) exists in nature in three forms: pyridoxine, pyridoxal and pyridoxamine. Under certain conditions, the three can be transformed into each other in vivo. Industrial synthesis is generally pyridoxine hydrochloride. Vitamin B 6 It is one of the essential vitamins for the human body and plays a key role in the growth of animals, so it is widely used in the fields of medicine, food, feed additives and cosmetics industries. [0003] At present, the industry usually uses chemical synthesis to produce vitamin B 6 , most of the research focuses on the improvement of the "oxazole method" synthesis process. Vitamin B 6 The advanced oxalyl oxazole process is used in the production, instead of the old route pyridone method, so that vitami...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D213/67
Inventor 戚聿新成鹏飞李新发吕强三
Owner XINFA PHARMA
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