Catalyst for selective oxidation of protection monosaccharide primary hydroxy group

A technology of sugar primary hydroxyl and selectivity, which is applied in the field of catalysts for the selective oxidation of monosaccharide primary hydroxyl, can solve the problems of harsh reaction conditions, many by-products, narrow pH range, etc., and achieve relaxed reaction conditions, fast reaction speed, The effect of fewer reaction steps

Active Publication Date: 2008-03-05
陕西汉江药业集团股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] 1. GB670929 uses nitric acid and sodium nitrite as oxidant, this method consumes a lot of nitric acid, the yield is low, there are many by-products, and a large amount of nitrogen dioxide (that is, the industry called "Huanglong") will be produced, which will cause serious pollution to the environment
[0005] 2. US2592249 and US2683150 use nitrogen dioxide gas as the oxidant, but nitrogen dioxide gas is inconvenient to operate and also causes serious pollution to the environment
[0011] Some of the above-mentioned methods using TEMPO need to use auxiliary oxidants, which will cause some problems: as adding sodium bromide, impurities such as Br will be introduced into the product; hydrogen peroxide is easy to explode in post-treatment, and the safety requirements for operation are very high; in addition The pH range in which the reaction occurs is narrow and the reaction conditions are relatively harsh
And the reaction yield of above-mentioned method is lower

Method used

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  • Catalyst for selective oxidation of protection monosaccharide primary hydroxy group
  • Catalyst for selective oxidation of protection monosaccharide primary hydroxy group

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Example 1 Preparation of 4-tert-butoxy-2,2,6,6-tetramethylpiperidine-N-oxide

[0032] At 0°C, add 300ml of dichloromethane, 60ml of pyridine, 30g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxide into a 1L three-necked flask, and then dropwise add 66g of p-toluenesulfonate A solution of acid chloride dissolved in 200ml of dichloromethane was reacted for 180 minutes. Then, a solution of 50 g of sodium tert-butoxide dissolved in 200 ml of dichloromethane was added dropwise to the solution, and the reaction was stirred for 120 minutes. After the reaction is complete, wash the reaction solution with water three times, dry the organic layer with anhydrous sodium sulfate, evaporate dichloromethane to dryness, add 100ml of n-hexane, freeze and crystallize, and filter to obtain 4-tert-butoxy-2,2,6,6- 34 g of red crystals of tetramethylpiperidine-N-oxide. 1 H NMR (CDCl 3 , 300MHz, δ) 1.22 (s, 9H) 1.73 (s, 12H) 1.95-2.20 (m, 4H) 2.83 (m, 1H); Elemental analysis: C, 68.36; H, ...

Embodiment 2

[0033] Example 2 Preparation of 4-isopropoxy-2,2,6,6-tetramethylpiperidine-N-oxide

[0034] At 0°C, add 300ml of dichloromethane, 60ml of pyridine, 30g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxide into a 1L three-necked flask, and then dropwise add 66g of p-toluenesulfonate A solution of acid chloride dissolved in 200ml of dichloromethane was reacted for 180 minutes. Then, a solution of 46.5 g of sodium isopropoxide dissolved in 200 ml of dichloromethane was added dropwise to the solution, and the reaction was stirred for 120 minutes. After the reaction is complete, wash the reaction solution with water three times, dry the organic layer with anhydrous sodium sulfate, evaporate dichloromethane to dryness, add 100ml of n-hexane, freeze and crystallize, and filter to obtain 4-isopropoxy-2,2,6,6- 28 g of red crystals of tetramethylpiperidine-N-oxide. 1 H NMR (CDCl 3 , 300MHz, δ) 1.17 (s, 6H) 1.71 (s, 12H) 1.95-2.20 (m, 4H) 2.83 (m, 1H) 3.20 (m, 1H); elemental analysis: C...

Embodiment 3

[0035] Example 3 Preparation of 4-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-N-oxide

[0036] At 0°C, add 300ml of dichloromethane, 60ml of pyridine, 30g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxide into a 1L three-necked flask, and then dropwise add 66g of p-toluenesulfonate A solution of acid chloride dissolved in 200ml of dichloromethane was reacted for 180 minutes. Add dropwise to this solution again the 200ml dichloromethane solution that contains 52.4g sodium cyclohexoxide, stir and react for 120 minutes. After the reaction is complete, wash the reaction solution with water three times, dry the organic layer with anhydrous sodium sulfate, evaporate dichloromethane to dryness, add 100ml of n-hexane, freeze and crystallize, and filter to obtain 4-isopropoxy-2,2,6,6- 32 g of red crystals of tetramethylpiperidine-N-oxide. 1 H NMR (CDCl 3 , 300MHz, δ) 1.39-1.46 (m, 8H) 1.71 (s, 12H) 1.73 (m, 2H) 1.95-2.20 (m, 4H) 2.79 (m, 1H) 2.83 (m, 1H); Elemental analysis: C , 7...

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PUM

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Abstract

The present invention relates to selective oxidation catalyst and process capable of protecting primary hydroxyl group in monosaccharide. It is found that using 4-alkoxyl group or acryloxy substituted 2, 2, 6, 6-tetramethyl piperidino-N-oxide as catalyst in the reaction of the protected monosaccharide and hypohaloid solution can oxidize the protected primary hydroxyl group in monosaccharide selectively into carboxyl group without need of auxiliary oxidant and with yield as high as 95 %.

Description

Technical field: [0001] The invention relates to a catalyst for the selective oxidation of the primary hydroxyl group of the protected monosaccharide, and also relates to a method for the selective oxidation of the primary hydroxyl group of the protected monosaccharide. Background technique: [0002] Monosaccharides are polyhydroxy compounds, and only the primary hydroxyl groups in their structures are selectively oxidized to monoglycosidic acid, which is of great significance because it is an important intermediate for the synthesis of many physiologically active substances. [0003] The catalysts and methods for the primary hydroxyl groups in the reported selective oxidation of monosaccharides are as follows: [0004] 1. GB670929 uses nitric acid and sodium nitrite as oxidants. This method consumes a large amount of nitric acid, has low yield and many by-products, and will produce a large amount of nitrogen dioxide (that is, "Huanglong" as it is called in the industry), ca...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D211/94B01J31/02C07H7/02
Inventor 谢文权李永胜
Owner 陕西汉江药业集团股份有限公司
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