Preparation method of 1-isopropyl-3-tert-butylthiourea

A technology of tert-butyl thiourea and isopropyl, applied in the field of preparation of pesticide intermediates, can solve the problems of affecting the reaction yield and efficiency, difficulty in three-waste treatment, easy generation of waste residues, etc., and achieves low cost, reduced risk, Environmentally friendly effect

Active Publication Date: 2015-11-04
LIANYUNGANG JINDUN AGROCHEMICAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] At present, manufacturers of buprofezin use reflux to carry water when producing tert-butyl isocyanate. The disadvantage is that anhydrous zinc chloride and aluminum trichloride are used in the production of tert-butyl isocyanate. If the flocculant is converted into a catalyst, it is easy to generate waste residue, which affects the reaction yield and efficiency
Most of the solvents for synthesizing 1-isopropyl-3-tert-butylthiourea use toluene, 1,2-dichloroethane or mineral spirits, and toluene is a precursor chemical, and the vapor pressures of these solvents are all It is relatively high and is flammable, so it is easy to cause production safety accidents, and it also brings difficulties to the treatment of three wastes

Method used

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  • Preparation method of 1-isopropyl-3-tert-butylthiourea

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Add 900kg of ammonium thiocyanate and 1000kg of water to the replacement kettle, stir to dissolve the ammonium thiocyanate; then add 1000kg of 85% tert-butanol, and stir for 20 minutes; slowly raise the temperature to 75°C, and then add 1443.4 industrial hydrochloric acid dropwise under reflux kg (mass concentration 29%), the dropping time is 2 hours, and after the dropping is completed, it is kept under reflux for 4 hours; then the temperature is lowered to 90°C, and it is left to stand for 30 minutes. The principle of different degrees of reduction is used to remove the water in layers, and the acidic waste water is sent to the waste water treatment tank. After washing again at 90°C, a light yellow transparent liquid is obtained; add 20kg of concentrated sulfuric acid to the light yellow transparent liquid, raise the temperature to 55°C, and keep it warm for 4 hours. , The insolubles were filtered off to obtain 1232.2 kg of 98.2% tert-butyl isothiocyanate, with a yield...

Embodiment 2

[0021] Add 900kg of ammonium thiocyanate and 450kg of water to the replacement kettle, stir to dissolve the ammonium thiocyanate; then add 1225kg of 85% tert-butanol and stir for 20 minutes; slowly raise the temperature to 75°C, and then add 1424kg of industrial hydrochloric acid dropwise under reflux (mass concentration 30%), the dropping time is 1 hour, and after the dropping is completed, it is kept under reflux for 2 hours; then the temperature is lowered to 90°C, and it is left to stand for 30 minutes. The specific gravity of various substances varies with the increase of temperature. The principle of level reduction is used to remove water in layers, and the acidic waste water is sent to the waste water treatment tank. After washing again at 90°C, a light yellow transparent liquid is obtained; add 6.1kg of concentrated sulfuric acid to the light yellow transparent liquid, heat up to 60°C, and keep warm for 6 hours. , The insolubles were filtered off to obtain 1238.4 kg of...

Embodiment 3

[0024] Add 900kg of ammonium thiocyanate and 1800kg of water to the replacement kettle, stir to dissolve the ammonium thiocyanate; then add 918.6kg of 85% tert-butanol, and stir for 20 minutes; slowly raise the temperature to 70°C, and then add industrial hydrochloric acid dropwise under reflux 2563kg (mass concentration 30%), the time of dropping is 3 hours, and after the dropping is completed, it is kept at reflux for 4 hours; then the temperature is lowered to 70°C, and it is left to stand for 30 minutes. The specific gravity of various substances increases with the temperature. The principle of different degrees of reduction is used to remove water in layers, and the acidic waste water is sent to the waste water treatment tank. After washing again at 90°C, a light yellow transparent liquid is obtained; add 6.1kg of concentrated sulfuric acid to the light yellow transparent liquid, heat up to 70°C, and keep warm for 3 After hours, the insoluble matter was filtered off to obt...

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Abstract

The invention discloses a preparation method of 1-isopropyl-3-tert-butylthiourea. Ammonium thiocyanate, tert-butyl alcohol and hydrochloric acid serve as raw materials and conduct the substitution reaction to generate a mixture of thiocyanic acid tert-butyl ester and isothiocyanic acid tert-butyl ester, the mixture stands still and is layered, water in the mixture is removed, then concentrated sulfuric acid serves as a transposition catalyst, thiocyanic acid tert-butyl ester is transposed to generate isothiocyanic acid tert-butyl ester, finally under the existence of isopropylamine, water serves as a solvent, the addition reaction is conducted, and a target product is synthesized. Water is removed in the reaction based on the principle that the specific gravity of matter is reduced to different degrees along with increase of temperature, and a large amount of heat energy is saved; the sulfuric acid serves as the transposition catalyst, and the reaction yield is increased to more than 90% from about 66% originally; the water serves as the solvent, risks are reduced in the production process of a production workshop, operation is safer, environment friendliness is achieved, cost is low, and quality is high; the total reaction yield of the method can be more than 88.9% by ammonium thiocyanate, and the method is more suitable for industrial production.

Description

[0001] technical field [0002] The invention relates to a preparation method of a pesticide intermediate, in particular to a preparation method of 1-isopropyl-3-tert-butylthiourea. Background technique [0003] 1-isopropyl-3-tert-butylthiourea is a key intermediate for the preparation of the insect growth regulator Buprofezin. The chemical name of Buprofezin is 2-tert-butylimino-3-isopropyl-5- Phenyl-1,3,5-thiadiazin-4-one is a thiadiazine insect growth regulator and belongs to insect molting inhibitor. By inhibiting the synthesis of chitin and interfering with metabolism, the pests cannot molt and metamorphosis normally and gradually die. It has the characteristics of high activity, high selectivity and long residual period. It is a chitin synthesis inhibitor of heterocyclic insects that does not kill adults, but can reduce oviposition and hinder egg hatching. Buprofezin is an agricultural insecticide with persistent larvicidal activity against Coleoptera, some Homopter...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C335/08
Inventor 王耀良石卫兵
Owner LIANYUNGANG JINDUN AGROCHEMICAL CO LTD
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