Synthesis method of dicyclohexyl carbodiimide

Abstract

The invention relates to a synthesis method of dicyclohexyl carbodiimide. The method comprises the following steps of sequentially adding a solvent and dicyclohexylurea into a reaction kettle at room temperature, then uniformly stirring, adding solid phosgene, then adding a catalyst and a reaction aid, increasing the temperature, and performing heat preservation and stirring reaction; introducing ammonia gas to regulate the pH value to 7.5-9 after the end of reaction, then performing suction filtration while hot, firstly performing evaporation at normal pressure on obtained filtrate to remove the solvent, then performing reduced pressure distillation at the pressure of 1.35-1.54kPa, collecting a fraction at the temperature of 153-156 DEG C, and performing vacuum drying in an oven to obtain dicyclohexyl carbodiimide. The process has the advantages of high yield, fast reaction and strong safety, overcomes the shortcomings that the existing solid phosgene is unstable in reaction and not high enough in yield, and has very broad industrial application prospects and market development potentials.

Description

technical field [0001] The invention relates to a method for synthesizing imine compounds, more specifically to a method for synthesizing dicyclohexylcarbodiimide, and belongs to the field of synthesis of organic chemical intermediates. Background technique [0002] Dicyclohexylcarbodiimide, also known as DCC, is a white crystal with a low melting point. It is a very important modern organic synthesis reagent. The cumulative diene structure in its molecule makes DCC have a strong chemical activity and can be combined with carboxyl Acid, hydrocyanic acid, hydrogen sulfide, alcohol, amine and other compounds react. As early as 1955, Sheeham used it for the synthesis of polypeptides, so it has been widely used as a dehydrating agent in synthetic reactions in the fields of organic, chemical, dye, pharmaceutical and biological synthesis; in addition, DCC can also be used as a dehydrating agent for polymers. Additives, such as used to accelerate the crosslinking of components suc...

AI Technical Summary

Problems solved by technology

The process adopts relatively safe solid phosgene, which can effectively ensure the safety and reliability of production, and fundamentally eliminate the serious problem of three wastes pollution, but the process yield is not high enough, the reaction is unstable and the yield difference is large (nearly 40% ), resulting in insufficient stability of industrial production and being easily affected by various factors

[0010] Although there are various synthetic methods of DCC in the prior art, these methods often have disadvantages that are not conducive to large-scale production, such as: 1. The product yield is not high enough to meet the needs of industrial applications; 2. The use of DCC is relatively toxic. The isocyanate or phosgene is a raw material, which brings potential safety hazards; 3. Some methods or processes have the problems of long production lines and cumbersome steps; 4. The process conditions are relatively harsh (such as high temperature), and the production energy consumption is high. reduced corporate profits

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