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Synthesis method of bismerthiazol

A synthetic method, the technology of thiacumazole, which is applied in the field of synthesis of thiacumazole, can solve the problems of difficult post-processing, low purity and yield of thiacumazole, unfavorable environmental protection, etc.

Active Publication Date: 2013-02-13
JIANGXI HEYI CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In the above method, thiacumazole must be synthesized in a strong acid medium, and the purity and yield of thiacumazole are relatively low; and a large amount of waste water is produced, which is difficult for post-treatment and is not conducive to environmental protection.

Method used

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  • Synthesis method of bismerthiazol
  • Synthesis method of bismerthiazol
  • Synthesis method of bismerthiazol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] Step 1: Add 125 grams of hydrazine hydrate (2mol) to a four-necked flask, add 100 grams of sulfuric acid (1.02mol) dropwise at 0°C, react at 0°C for 3 hours, add 154 grams of ammonium thiocyanate (2mol) and 10 1 g of acetone (0.17 mol) mixed solution was reacted at 70°C for 3 hours, cooled to 0°C, crystallized, and filtered to obtain 176.5 g of thiosemicarbazide (1.84 mol), with a purity of 95% and a yield of 92%.

[0036] In the second step, put 144 grams of thiosemicarbazide (1.5 mol), 36.5 grams of hydrochloric acid (1 mol), and 1 gram of dimethylformamide (0.015 mol) into the reaction bottle, and drop 23 grams of polymer Formaldehyde (0.75mol) was added dropwise, heated to 60°C, reacted for 3 hours, cooled and crystallized and filtered to obtain 138 g of thiosemicarbazone (0.75mol), with a purity of 95% and a yield of 90%.

[0037] Step 3: Put 102 grams of thiosemicarbazone (0.5 mol) and 75 grams of toluene into the reaction bottle, and add 77 grams of carbon disulf...

Embodiment 2

[0039] Step 1: Add 125 grams of hydrazine hydrate (2mol) to a four-neck flask, add 200 grams of sulfuric acid (2.04mol) dropwise at 0°C, react at 20°C for 1.5 hours, add 154 grams of ammonium thiocyanate (2mol) and 38 gram of butanone (0.54mol) mixed solution was reacted at 90°C for 2 hours, cooled to 0°C, crystallized and filtered to obtain 172.7g of thiosemicarbazide (1.77mol) with a purity of 95% and a yield of 90%.

[0040] In the second step, put 144 grams of thiosemicarbazide (1.5 mol), 36.5 grams of hydrochloric acid (1 mol), 1 gram of DMSO (0.013 mol) into the reaction bottle, and drop 50 grams of formaldehyde (1.63 mol) at 40 ° C for 2 hours. After the dropwise addition was completed, the temperature was raised to 70°C, and the reaction was carried out for 3 hours, cooled, crystallized and filtered to obtain 140.3 g of thiosemicarbazone (0.76 mol), with a purity of 92% and a yield of 91.5%.

[0041] Step 3: Put 102 grams of thiosemicarbazone (0.5mol) and 75 grams of t...

Embodiment 3

[0043] Step 1: Add 125 grams of hydrazine hydrate (2mol) to a four-neck flask, add 390 grams of sulfuric acid (4mol) dropwise at 10°C, react at 10°C for 3 hours, add 154 grams of ammonium thiocyanate (2mol) and 10 grams Acetone (0.17mol) mixed solution was reacted at 50°C for 3 hours, cooled to 0°C, crystallized, and filtered to obtain 177.5 g of thiosemicarbazide (1.85mol), with a purity of 95% and a yield of 92.5%.

[0044] In the second step, put 144 grams of thiosemicarbazide (1.5mol), 365 grams of hydrochloric acid (2mol), and 1 gram of pyridine (0.013mol) into the reaction bottle, and add 120 grams of paraformaldehyde (4mol) dropwise at 50°C for 3 hours After the dropwise addition, the temperature was raised to 80°C, and the reaction was carried out for 3 hours, cooled, crystallized and filtered to obtain 141 g of thiosemicarbazone (0.77 mol), with a purity of 94.8% and a yield of 92%.

[0045]The third step: put 102 grams of thiosemicarbazone (0.5 mol) and 75 grams of c...

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Abstract

The invention discloses a synthesis method of bismerthiazol. The method comprises the steps that firstly, hydrazine hydrate and sulphuric acid are reacted, so as to produce hydrazine sulfate; the produce hydrazine sulfate is reacted with aliphatic ketone solution of ammonium thiocyanate, so as to obtain thiosemicarbazide, and the aliphatic ketone adopts acetone or butanone; then the thiosemicarbazide is reacted with formaldehyde or paraformal-dehyde under hydrochloric acid and the effect of catalyst, so as to obtain conteben, and the catalyst adopts one or more of dimethyl sulfoxide, dimethyl formamide and pyridine; and finally, the conteben is reacted with carbon disulfide in aromatic solvent, so as to obtain the bismerthiazol. The invention further discloses an optimal enforcement mode. The synthesis method has the advantages that the yield in each step is more than 80 percent, the purity of the final product bismerthiazol is more than 90 percent, the reaction condition is mild, wastewater and waste gas are hardly produced, and the synthesis method is environmentally friendly and suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of organic chemistry, and in particular relates to a synthesis method of thiacumazole. Background technique [0002] Thiacumazole, also known as Yecumazole, is systematically named N,N'-methylene-bis(2-amino-5-thio-1,3,4-triazole), and its structural formula is shown in 1. It is a systemic fungicide, mainly used to prevent and control plant bacterial diseases, and is an excellent agent for preventing and controlling rice bacterial blight, rice bacterial streak and citrus canker. It has the characteristics of strong systemic absorption, long-lasting effect, stable drug effect, and no phytotoxicity to crops. [0003] [0004] The synthesis of thiacumazole is generally prepared from hydrazine hydrate, sodium thiocyanate, formaldehyde, etc.: hydrazine hydrate reacts with sulfuric acid to generate hydrazine sulfate, and then reacts with ammonium thiocyanate in the presence of a catalyst to obtain an intermediate Thioa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D285/135
Inventor 廖永彭涛冯亚东钟振英
Owner JIANGXI HEYI CHEM
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