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Preparation method of high purity N,N'-dicyclohexylthiourea

A technology of dicyclohexylthiourea and cyclohexylamine, which is applied in the direction of organic chemistry, can solve the problems of easy loss of solvents, cumbersome operation, and inapplicability to industrial production, and achieve the goals of reducing energy consumption, ensuring removal efficiency, and saving costs Effect

Active Publication Date: 2014-02-12
SHANDONG HUIHAI PHARMA & CHEM
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AI Technical Summary

Problems solved by technology

[0002] At present, the large-scale production of N, N′-dicyclohexylthiourea at home and abroad is obtained by reacting cyclohexylamine and carbon disulfide in the presence of aromatic hydrocarbon solvents (such as xylene, benzene, toluene, etc.). Although industrial production can be carried out, its disadvantages are obvious, mainly: 1. The solvents used are highly flammable chemicals, and safety is difficult to guarantee; 2. The solvents used are highly toxic; 3. The solvents used are easily flammable during the production process. loss, high cost
[0003] J. Org. Chem., 1999, 64 (3): pp 1029-1032 discloses that cyclohexylamine and carbon disulfide are used as raw materials, zinc oxide and aluminum oxide are used as catalysts, and water is used as a solvent to generate The method of N, N'-dicyclohexylthiourea, but the disadvantage of this method is that it is not suitable for industrial production
[0004] J. Org. Chem., 2010, 75 (7), pp 2327–2332 discloses that the corresponding amine and carbon disulfide are used as raw materials, sodium hydroxide is used as an acid-binding agent, and water is used as a solvent to generate under reflux conditions to replace sulfur The method of urea, but the disadvantage of this method is that the operation is cumbersome. After the reaction is completed, it is necessary to neutralize the sodium hydroxide with acid and then use an organic solvent to extract the product and then purify it. The yield is up to 90%, which is only suitable for small-scale laboratory production. , not suitable for industrial production
[0005] Volume 26, No. 6 of "Fine Petrochemical Industry", pages 25-26, discloses that cyclohexylamine and carbon disulfide are used as raw materials, and water is used as a solvent. o C generates N, N'-dicyclohexylthiourea, but the disadvantage of this method is that hydrogen sulfide cannot be completely removed under pure water phase conditions, so that the yield is low (up to 93%), and hydrogen sulfide Incomplete removal is prone to safety accidents during industrial production, so it is not suitable for industrial production

Method used

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  • Preparation method of high purity N,N'-dicyclohexylthiourea

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Add 500kg of solvent water and 200kg of cyclohexylamine to the reaction kettle, start stirring, raise the temperature to 25°C, start to add 82 kg of carbon disulfide dropwise, control the dropping time for 2h, and control the temperature at 25-30°C; Insulate at -30°C for 1 hour, filter after the reaction is complete, collect the filtered intermediate salt solid and put it back into the reaction kettle, open the vacuum valve, keep the vacuum negative pressure at -0.05MPa, and raise the temperature to 90 o C was dried for 3 hours to remove hydrogen sulfide to obtain 241 kg of N, N'-dicyclohexylthiourea product with a yield of 99.14% and a purity of 99.68%.

[0016] The obtained mother liquor is reused in the following 10 reaction cycles without any treatment, and an average of 241.55 kg of product can be obtained, with a yield of 99.36%.

[0017] Mother liquor cycle times Product weight / kg Product yield / % purity / % 0 241 99.14 99.68 1 241 99.14 ...

Embodiment 2

[0019] Add 500kg of solvent water and 200kg of cyclohexylamine to the reaction kettle, start stirring, cool down to 10°C, start to add 80 kg of carbon disulfide dropwise, control the dropping time for 3 hours, and control the temperature at 10-15°C; Insulate at -15°C for 1h, filter after the reaction is complete, collect the filtered intermediate salt solid and put it back into the reaction kettle, open the vacuum valve, keep the vacuum negative pressure at -0.03MPa, and raise the temperature to 60 o C was dried for 5 hours to remove hydrogen sulfide to obtain 240.3 kg of N, N'-dicyclohexylthiourea product with a yield of 99.08% and a purity of 99.56%.

Embodiment 3

[0021] Add 500kg of solvent water and 160kg of cyclohexylamine to the reaction kettle, start stirring, raise the temperature to 30°C, start to add 68 kg of carbon disulfide dropwise, control the dropping time for 1.5h, and control the temperature at 30-40°C; Insulate at 25-30°C for 2 hours, filter after the reaction is completed, collect the filtered intermediate salt solid and put it back into the reactor, open the vacuum valve, keep the vacuum negative pressure at -0.07MPa, and raise the temperature to 80 o C was dried for 2 hours to remove hydrogen sulfide to obtain 192.3 kg of N,N'-dicyclohexylthiourea product with a yield of 99.08% and a purity of 99.56%.

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Abstract

The invention provides a preparation method of high purity N,N'-dicyclohexylthiourea. The method comprises the following steps:1) mixing water and cyclohexylamine, then adding carbon disulfide in a dropwise manner at a temperature of 0-40 DEG C for 1-3 hours, controlling the temperature to 0-40 DEG C and continuously carrying out the reaction for 1-3 hours, wherein a weight ratio of the water to the cyclohexylamine is 2.5 to 3.8:1, and a weight ratio of the carbon disulfide to the cyclohexylamine is 0.3 to 0.45:1; 2) and carrying out filtration to remove the mother liquor to obtain an intermediate salt, and carrying out vacuum hydrogen sulfide removing on the under intermediate salt to obtain the N,N'-dicyclohexyl thiourea. With the technical scheme, disadvantages of flammability and explosiveness, and high cost of the organic solvent are avoided. Yield of the product provided in the invention is greater than 99%, and purity is greater than 99.5%. With the method, the same effect with using an organic solvent is realized, and the mother liquor can be reused, such that the organic solvent is wholly substituted and no waste liquid is discharged. According to the invention, by using the technology of vacuum hydrogen sulfide removing at the low temperature, energy consumption is lowered and removal efficiency of removing the hydrogen sulfide is guaranteed.

Description

technical field [0001] The invention relates to a preparation method of a biological polypeptide condensing agent intermediate, in particular to a preparation method of high-purity N, N'-dicyclohexylthiourea. Background technique [0002] At present, the large-scale production of N, N′-dicyclohexylthiourea at home and abroad is obtained by reacting cyclohexylamine and carbon disulfide in the presence of aromatic hydrocarbon solvents (such as xylene, benzene, toluene, etc.). Although industrial production can be carried out, its disadvantages are obvious, mainly: 1. The solvents used are highly flammable chemicals, and safety is difficult to guarantee; 2. The solvents used are highly toxic; 3. The solvents used are easily flammable during the production process. loss, higher cost. [0003] J. Org. Chem., 1999, 64 (3): pp 1029-1032 discloses that cyclohexylamine and carbon disulfide are used as raw materials, zinc oxide and aluminum oxide are used as catalysts, and water is u...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C335/14
Inventor 牟应科郑庚修卢言建李新忠张国辉
Owner SHANDONG HUIHAI PHARMA & CHEM
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