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Synthetic method of 3-ethyl-5-(2-hydroxyethyl)-4-methyl thiazole bromide

A technology of methylthiazole and a synthesis method, applied in directions such as organic chemistry, can solve the problems of unsuitable large-scale production of industrialization, high risk of diethyl ether, loss of ethyl bromide, etc., and achieves improved appearance quality, good production safety, The effect of low production cost

Inactive Publication Date: 2011-04-20
HANGZHOU NORMAL UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If carry out industrialized production to this product with this method, then there are following problems: (1) this method only needs 24 hours for reflux time, so energy consumption is big, and production cycle is long, (2) this method uses a large amount of acetonitrile to make The reaction solvent will consume a large amount of isopropanol and ether in the aftertreatment process, so that not only the production cost is high, but also because the ether used is dangerous, causing great pressure to safe production, (3) the reaction of the method It is an open system, and the boiling point of ethyl bromide is low, so a part of ethyl bromide will be lost during the reflux process, resulting in a low reaction yield
In summary, the methods in existing literature are not suitable for industrialized large-scale production of this product

Method used

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  • Synthetic method of 3-ethyl-5-(2-hydroxyethyl)-4-methyl thiazole bromide
  • Synthetic method of 3-ethyl-5-(2-hydroxyethyl)-4-methyl thiazole bromide
  • Synthetic method of 3-ethyl-5-(2-hydroxyethyl)-4-methyl thiazole bromide

Examples

Experimental program
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Effect test

Embodiment 1

[0024] Put 65 kg of 5-(2-hydroxyethyl)-4-methylthiazole and 65 kg of bromoethane into a dry and clean 300L autoclave, and replace the air in the autoclave with nitrogen. Slowly raise the temperature to 50°C, keep it warm at 50°C for 2 hours, when the reaction is over, turn on the cooling water and cool down to 30°C. Put 20 kg of absolute ethanol into a 300L autoclave, raise the temperature to 50°C, and transfer the material liquid to a 300L enamel Then put 60Kg of ethyl acetate into the reaction kettle, stir and cool, lower the temperature to 10°C, keep warm for 2 hours, filter with suction, keep the filtrate, rinse the filter cake with a small amount of ethyl acetate, spin dry, and quickly transfer to a vacuum dryer , dried at a temperature not exceeding 60° C. for 10 hours to obtain 96 Kg of the product with a yield of 84%.

Embodiment 2

[0026] Put 65 kilograms of 5-(2-hydroxyethyl)-4-methylthiazole and 80 kilograms of ethyl bromide into a dry and clean 300L autoclave. Replace the air in the pot with nitrogen. Slowly raise the temperature to 50°C. 1 hour at 50°C, then raise the temperature to 70°C, keep warm at 70°C for 1 hour, after the reaction is over, turn on the cooling water and cool down to 30°C. Put 20 kg of anhydrous methanol into a 300L autoclave, heat up to 50°C, Transfer the material liquid to a 300L enamel reaction kettle, then put in 100Kg of acetone, stir and cool, lower the temperature to 10°C, keep warm for 2 hours, filter with suction, keep the filtrate, rinse the filter cake with a small amount of acetone, spin dry, and transfer quickly In a vacuum dryer, dry at a temperature not exceeding 60° C. for 10 hours to obtain 100 Kg of the product with a yield of 87%.

Embodiment 3

[0028] Put 65 kilograms of 5-(2-hydroxyethyl)-4-methylthiazole and 100 kilograms of ethyl bromide into a dry and clean 300L autoclave. Replace the air in the pot with nitrogen. Slowly raise the temperature to 50°C, keep it at 50°C for 1 hour, then raise the temperature to 60°C, keep it at 60°C for 1 hour, continue to raise the temperature to 80°C, keep it at 80°C for 2 hours, the reaction is over, turn on the cooling water to cool down to 30°C. Put 20 kg of absolute ethanol into a 300L autoclave, raise the temperature to 50°C, transfer the feed liquid to a 300L enamel reaction kettle, then put in 80Kg of ethyl acetate, stir and cool, and lower the temperature to 10°C. Insulate for 2 hours, filter with suction, retain the filtrate, rinse the filter cake with a small amount of ethyl acetate, spin dry, quickly transfer to a vacuum dryer, and dry at a temperature not exceeding 60°C for 10 hours to obtain 105Kg of the product with a yield of 92 %.

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Abstract

The invention discloses a method for synthesizing 3-ethyl-5-(2-hydroxyethyl)-4-methylthiazol bromide expressed in a structural formula (I). The method comprises: in a sealed reactor, 5-(2-hydroxyethyl)-4-methylthiazol expressed in a structural formula (II) and ethyl bromide react for 2 to 6 hours at a temperature of between 50 and 100 DEG C under the protection of inert gases; and after the reaction is ended, a reaction solution is subjected to crystallization and separation so as to obtain the 3-ethyl-5-(2-hydroxyethyl)-4-methylthiazol bromide. The method has the advantages of low production cost, short production period, simple and convenient production operation, good production safety and the like, and is quite suitable for industrialized production of products.

Description

(1) Technical field [0001] The invention relates to a synthesis method of 3-ethyl-5-(2-hydroxyethyl)-4-methylthiazole bromide. (2) Background technology [0002] 3-Ethyl-5-(2-hydroxyethyl)-4-methylthiazole bromide is a useful fine chemical product, and its structural formula is shown in formula (I), [0003] [0004] 3-Ethyl-5-(2-hydroxyethyl)-4-methylthiazole bromide can be obtained by reacting 5-(2-hydroxyethyl)-4-methylthiazole with bromoethane under reflux conditions, The method is briefly described as follows: 5-(2-hydroxyethyl)-4-methylthiazole and bromoethane were refluxed in acetonitrile solution, and after 24 hours, the final product 3-ethyl-5-(2-hydroxyethyl base)-4-methylthiazole bromide with a yield of 76% (Chem. Ber. 109, 2890-2896, 1976). If carry out industrialized production to this product with this method, then there are following problems: (1) this method only needs 24 hours for reflux time, so energy consumption is big, and production cycle is long, ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D277/24
Inventor 潘建林沈华锋喻彪俞建忠
Owner HANGZHOU NORMAL UNIVERSITY