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Preparation method of 2-sulfydryl-5-methyl-1, 3, 4-thiadiazole

A technology of thiadiazole and methyl, which is applied in the field of preparation of 2-mercapto-5-methyl-1,3,4-thiadiazole, which can solve the problems of complex operation, high production cost and long reaction time , to achieve the effect of simplifying the process steps, reducing the cost of raw materials, and simple reaction operation

Inactive Publication Date: 2013-10-23
ZHEJIANG HAILAN CHEM GRP
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to aim at the existing 2-mercapto-5-methyl-1,3,4-thiadiazole preparation method with long reaction time, high energy consumption, complex and cumbersome operation, high production cost, and at the same time The shortcomings of easily producing more waste and pollutants provide a 2-mercapto-5-methyl-1,3, which has simple process operation, short reaction time, low production cost, and less waste and pollutant generation. The preparation method of 4-thiadiazole

Method used

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  • Preparation method of 2-sulfydryl-5-methyl-1, 3, 4-thiadiazole
  • Preparation method of 2-sulfydryl-5-methyl-1, 3, 4-thiadiazole

Examples

Experimental program
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Effect test

Embodiment 1

[0020] Put 50 grams of 100% hydrazine hydrate and 120 grams of 20% ammonia water in a 500 milliliter synthesis reaction bottle successively, and stir under ice water cooling to lower the temperature to below 5°C. Start to add 90 grams of carbon disulfide dropwise, and keep stirring at below 5° C. for 1 hour after addition. An aqueous solution of ammonium hydrazinodithioformate was obtained.

[0021] Transfer the solution obtained above into a 1000 ml reaction flask, add 100 g of acetonitrile, stir naturally for half an hour, then raise the temperature to 85-90°C and keep it warm for 1 hour. Then cool the solution down to below 40°C, add 30% hydrochloric acid dropwise in the range of 30°C to 35°C, adjust the pH to 4 to 4.5, stir for half an hour, filter with suction, and wash with water three times to obtain 130g of wet thiadiazole.

[0022] The obtained wet product was dissolved with ammonia water, decolorized, kept warm, filtered, acidified, suction filtered and dried to obt...

Embodiment 2

[0024] Put 50 grams of 100% hydrazine hydrate and 120 grams of 20% ammonia water in a 500 milliliter synthesis reaction bottle successively, and stir under ice water cooling to lower the temperature to below 5°C. Start to add 80 grams of carbon disulfide dropwise, and keep stirring at below 5° C. for 1 hour after addition. An aqueous solution of ammonium hydrazinodithioformate was obtained.

[0025] Transfer the solution obtained above into a 1000 ml reaction flask, add 100 g of acetonitrile, stir naturally for half an hour, then raise the temperature to 85-90°C and keep it warm for 1 hour. Then the solution was cooled to below 40°C, 35% hydrochloric acid was added dropwise in the range of 30°C to 35°C, the pH was adjusted to 4 to 4.5, stirred for half an hour, suction filtered, washed 3 times with water, and 142g of wet thiadiazole was obtained.

[0026] The obtained wet product was dissolved with ammonia water, decolorized, kept warm, filtered, acidified, suction filtered, ...

Embodiment 3

[0028] Put 50 grams of 100% hydrazine hydrate and 120 grams of 20% ammonia water in a 500 milliliter synthesis reaction bottle successively, and stir under ice water cooling to lower the temperature to below 5°C. Start to add 80 grams of carbon disulfide dropwise, and keep stirring at below 5° C. for 1 hour after addition. An aqueous solution of ammonium hydrazinodithioformate was obtained.

[0029] Transfer the solution obtained above into a 1000 ml reaction flask, add 105 g of acetonitrile, stir naturally for half an hour, then raise the temperature to 85-90° C. for 1 hour. Then the solution was cooled to below 40°C, 35% hydrochloric acid was added dropwise in the range of 30°C to 35°C, the pH was adjusted to 4 to 4.5, stirred for half an hour, suction filtered, and washed with water three times to obtain thiadiazole wet product 135g.

[0030] The obtained wet product was dissolved with ammonia water, decolorized, kept warm, filtered, acidified, suction filtered, and dried ...

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Abstract

The invention relates to a preparation method of 2-sulfydryl-5-methyl-1, 3, 4-thiadiazole. The preparation method of the 2-sulfydryl-5-methyl-1, 3, 4-thiadiazole, provided by the invention, comprises the following steps of: (1) placing the weighted hydrazine hydrate and ammonium hydroxide into a reaction vessel to be uniformly mixed, dropwise adding carbon disulfide at low temperature, after the dropwise adding operation is ended, stirring and preserving the heat to obtain a water solution of diazanyl dithiocarbamate; (2) adding acetonitrile into the reaction vessel, reacting while stirring, heating, stirring, preserving heat and reflowing to obtain a water solution of 2-sulfydryl-5-methyl-1, 3, 4-thiadiazole aluminum salt; and (3) when the reaction vessel in the step (2) is cooled to be below 40 DEG C, dropwise adding hydrochloric acid for acidifying to obtain a 2-methyl-5-sulfydryl-1, 3, 4-thiadiazole suspension, filtering and washing to obtain milk white crystal powder, namely a crude product of the 2-sulfydryl-5-methyl-1, 3, 4-thiadiazole, and then, purifying and drying the crude product to obtain white crystal powder, namely the 2-sulfydryl-5-methyl-1, 3, 4-thiadiazole. The preparation method has the characteristics of simplicity and convenience in process operation, short reaction time, low production cost and few wastes and pollutants.

Description

technical field [0001] The invention relates to the technical fields of medicine and chemical industry, in particular to a preparation method of 2-mercapto-5-methyl-1,3,4-thiadiazole. Background technique [0002] 2-Mercapto-5-methyl-1,3,4-thiadiazole is a white crystalline powder, an important intermediate in the synthesis of antibiotic drug cefazolin sodium, and has important industrial and medical value. [0003] The existing preparation method of 2-mercapto-5-methyl-1,3,4-thiadiazole mainly adopts hydrazine hydrate, ethyl acetate, methanol or ethanol solvent, lye, carbon disulfide, and acid solution as raw materials, wherein, The solvent is methanol or ethanol, the lye is potassium hydroxide or liquid ammonia, the acid solution is concentrated sulfuric acid or concentrated hydrochloric acid, and it is obtained from ethyl acetate through hydrazination, addition, cyclization, and hydrolysis. The existing preparation method of 2-mercapto-5-methyl-1,3,4-thiadiazole has the ...

Claims

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Application Information

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IPC IPC(8): C07D277/36
Inventor 吴晓秉朱先华刘水王美林
Owner ZHEJIANG HAILAN CHEM GRP
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