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ChemicalBook CAS DataBase List Ethylene thiourea
96-45-7

Ethylene thiourea synthesis

8synthesis methods
-

Yield:96-45-7 99.1%

Steps:

5-6; 3 Embodiment 6

Put 2300L of the last batch of reaction filtrate and 540kg of ethylenediamine into the kettle, stir at room temperature for 0.5h to make the system evenly mixed, slowly add 675L of carbon disulfide, control the temperature below 45, and keep the temperature for 1h after the addition. The temperature was raised to reflux, the excess carbon disulfide in the system was recovered, and the temperature of the system was gradually increased from 46 °C to 70 °C, and the required time was 3h. The temperature of the system continued to rise to 80°C, and the temperature was maintained until the system no longer produced hydrogen sulfide gas. The temperature was raised to 90°C, and the temperature was maintained until the system no longer produced hydrogen sulfide gas. Reduce the opening of the vent valve to form a semi-closed system, heat up to 100°C, and keep the temperature until the system no longer produces hydrogen sulfide gas. Close the vent valve to make the system a closed system, raise the temperature to 100-102°C, and keep the temperature for 2 hours. If the system pressure exceeds 0.2Mpa, open the vent valve to relieve pressure, then continue to close the vent valve and keep the temperature at 101-103°C. End the reaction. Cool to below 30°C, filter and dry to obtain 910kg of white powdery tetrahydroimidazole-2-thione with a yield of 99.1%

References:

CN114702421,2022,A Location in patent:Paragraph 0041-0044; 0053-0054

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