A kind of benzylation method of monosaccharide methyl glycoside

A monosaccharide methyl glycoside and benzylation technology, applied in the chemical field, can solve the problems of unstable solvent, increase of by-product toluene, low boiling point of solvent, etc., and achieve the effect of simplifying post-processing operation, reducing sodium hydride, and suitable boiling point

Active Publication Date: 2018-03-20
浙江合糖科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The technical problem to be solved by the present invention is: the proportion of toluene in the solvent used in the prior art is constantly increasing during the mechanical application process, which affects the process stability; and benzyl chloride or benzyl bromide to generate dibenzyl ether as a by-product; or the solvent used has a low boiling point, which limits the selectable temperature range of the benzylation reaction; or the solvent itself is unstable under alkaline conditions ; or the used solvent has a narrow range of application, and can only synthesize all-benzyl products, and it is difficult to recover, has high toxicity, consumes raw material sodium hydrogen, and increases by-product toluene

Method used

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  • A kind of benzylation method of monosaccharide methyl glycoside
  • A kind of benzylation method of monosaccharide methyl glycoside
  • A kind of benzylation method of monosaccharide methyl glycoside

Examples

Experimental program
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Effect test

Embodiment 1

[0040] Methyl-2,3,4,6-tetra-O-benzyl-α-D-glucopyranoside

[0041] In a 250ml three-neck flask equipped with a stirrer, a thermometer, and a condenser tube, add methyl-α-D-glucopyranoside 9.7g (50.0mmol) and sodium hydride paraffin oil dispersion (sodium hydride content 55wt%) successively 9.16g (209.9mmol), 60ml of toluene, 27.85g (220.0mmol) of benzyl chloride, heated to about 105-110°C, tracked by liquid chromatography, and kept warm until the reaction was complete. After the heat preservation reaction is completed, cool down to about 60°C, slowly add water dropwise, and react with the residual sodium hydride until no bubbles are formed. The solid matter was removed by filtration, and the filter cake was washed with 15 ml x 2 times of toluene, and the organic layers were combined. The organic layer was heated to 65-70° C., washed with water until neutral, and washed with 20 ml of water each time, and washed 3-4 times (the first washing water was discarded, and the other was...

Embodiment 2

[0043] Methyl-2,3,4,6-tetra-O-benzyl-α-D-glucopyranoside

[0044] In a 250ml three-necked flask equipped with a stirrer, a thermometer, and a condenser tube, add methyl-α-D-glucopyranoside 9.7g (50.0mmol) and sodium hydride paraffin oil dispersion (sodium hydride content 55%) in sequence 9.16g (209.9mmol), 60ml of toluene, 26.56g (210.0mmol) of benzyl chloride, heated to about 90-95°C, tracked by liquid chromatography, and kept warm until the reaction was complete. After the heat preservation reaction is completed, cool down to about 60°C, slowly add water dropwise, and react with the residual sodium hydride until no bubbles are formed. The solid matter was removed by filtration, and the filter cake was washed with 15 ml x 2 times of toluene, and the organic layers were combined. The organic layer was heated to 65-70° C., washed with water until neutral, and washed with 20 ml of water each time, and washed 3-4 times (the first washing water was discarded, and the other washin...

Embodiment 3

[0046] Methyl-2,3,4,6-tetra-O-benzyl-α-D-galactopyranoside

[0047] In a 250ml three-neck flask equipped with a stirrer, a thermometer, and a reflux separator (equipped with a condenser tube), 10.6g (50.0mmol) of methyl-α-D-galactopyranoside monohydrate, toluene 100ml, heat up to 90-95°C, control the vacuum degree -0.03--0.04Mpa, reflux and divide water to remove the crystal water in methyl-α-D-galactopyranoside monohydrate. After dehydration is completed, cool down to 35-40°C, and change the reflux water separator to a reflux condensing device. Add sodium hydride paraffin oil dispersion (content 55%) 10.0g (229.2mmol) and benzyl chloride 30.5g (240.9mmol) successively, heat up to about 90-95°C, follow by liquid chromatography, keep warm until the reaction is complete. After the heat preservation reaction is completed, cool down to about 60°C, slowly add water dropwise, and react with the residual sodium hydride until no bubbles are formed. The solid matter was removed by fi...

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Abstract

The invention discloses a method for benzylation of monosaccharide methyl glycoside: add monosaccharide methyl glycoside, sodium hydride, toluene and benzyl chloride in sequence in a reactor, heat up to a reaction temperature of 60-130°C, and keep warm until the reaction is complete , after the end of the reaction, the post-treatment of the reaction solution produces a benzylated product of the monosaccharide methyl glycoside; the benzylated product of the monosaccharide methyl glycoside is that all the hydroxyl-OH on the monosaccharide methyl glycoside are all benzylated to generate ‑O ‑Bn product, Bn represents benzyl. Both the reaction solvent and the extraction solvent of the present invention are toluene, which simplifies the post-processing operation. The by-product toluene in the reaction process is consistent with the reaction solvent, and the recovered toluene can be directly used as the next batch of reaction solvent without removing water, thereby simplifying the operation. The purpose of reducing the unit consumption of sodium hydride and benzyl chloride, effectively reducing the generation of by-product dibenzyl ether, and reducing pollution.

Description

(1) Technical field [0001] The invention belongs to the field of chemistry, in particular to a method for benzylation of monosaccharide methyl glycoside. (2) Background technology [0002] The benzyl ether formed by the benzylation reaction of the sugar hydroxyl group is very stable to most acids and bases; it is also not affected by negative hydrogen reducing agents and mild oxidants, so it has a significant advantage in stability. The conditions for forming the protecting group are mild and the operation is simple. The benzylating reagents benzyl chloride and benzyl bromide are relatively cheap and easy to obtain. Pd / C-H 2 Hydrogenolysis is a characteristic deprotection reaction, and most protecting groups are compatible with it. Therefore, benzylation reaction is widely used in the synthesis of sugar derivatives. [0003] The commonly used benzylation method of monosaccharide methyl glycoside is the classic Williamson synthesis. First, the hydroxyl group and sodium h...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07H15/18C07H1/00
Inventor 姜国平曹凌峰
Owner 浙江合糖科技有限公司
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