Novel synthesis method of N, N'-dicyclohexylcarbo-diimide

Abstract

The invention discloses a novel synthesis method of N, N'-dicyclohexylcarbo-diimide. The novel synthesis method comprises the steps of adding water and cyclohexylamine, starting to stir; dropwise adding carbon disulfide, controlling temperature and pressure, and filtering after cooling to obtain N, N'-dicyclohyxylthiourea; after mixing N, N'-dicyclohyxylthiourea and an adjuvant, adding the mixture into a sodium hypochlorite solution, separating the liquid by heating, adding an organic phase into a hot sodium sulfide solution, separating the liquid while heating, extracting the organic phase, washing the organic phase twice by using a hot sodium hydroxide solution to obtain a crude product, wherein each washing time is 15 minutes; and rectifying to obtain a finished product, namely N, N'-dicyclohexylcarbo-diimide. By using the synthesis method, no organic solvents are used, and the dangers that the organic solvents are flammable and combustible are eliminated; the solvent does not need to be evaporated before N, N'-dicyclohexylcarbo-diimide is rectified, so that the energy waste, the cost and the product loss are reduced, and no solvent residues are left; the novel synthesis method is wide in application range; and the yield and purity of N, N'-dicyclohexylcarbo-diimide are increased, the yield is not lower than 93.5%, and the purity is not lower than 99.3%.

Description

technical field [0001] The invention belongs to the field of fine chemical technology, in particular to a new synthesis method of N, N'-dicyclohexylcarbodiimide. Background technique [0002] N,N'-dicyclohexylcarbodiimide is a colorless or light yellow solid, liquid above 35°C, N,N'-dicyclohexylcarbodiimide is used for the synthesis and dehydration of amikacin and amino acids, It is a good low-temperature biochemical dehydrating agent, and it is also used in the synthesis of acids, anhydrides, aldehydes, ketones, etc. In Japan, the dehydrating agent used for glutathione accounts for 90% of the total consumption. When this product is used as a dehydration condensation agent, it can be prepared after a short period of reaction at room temperature, and the product after the reaction is dicyclohexyl urea. Because the product has very little solubility in organic solvents, the reaction product is easy to separate; at the same time, because the product is hardly soluble in water...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a kind of N, N'-dicyclohexylcarbodiimide by overcoming the problems of poor security, low purity, solvent residue, low yield, large environmental pollution and high production cost in the prior art. Preparation methods, improving raw materials and adding catalysts, improving product quality and yield, reducing solvent residues, improving safety and working environment

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