Method of preparing 1-(4-chloro-phenyl)-3-(3,4-dichloro-phenyl)-urea

Abstract

This invention relates to a method for preparing 3, 4, 4'-trichloro-Triclosan benzene and two urea as a antiseptic including two-step reaction method, the first one is to take chloraniline as the raw material and toluene as the solvent to be reacted with solid phosgene to remove un-reacted solid phosgene and generated HCl gas to be decolored and filter solid impurities to get chlorophenyl phenyl isocyanate-toluene mother liquid, the second step is to synthesize said mother liquid with the 3, 4-dichloroaniline directly then to be filtered, cleaned and dried to get 3, 4, 4'-trichloro-triclosan benzene and two urea and the solvent is distilled and washed by acid, alkali and water to be reused.

Description

technical field [0001] The invention relates to the technical field of organic chemistry, in particular to a preparation method of 3,4,4'-trichlorodiphenylurea. Background technique [0002] 3,4,4'-Trichlorophenylenediurea is an important daily chemical fungicide, its full name is N-(4-chlorophenyl)-N'-(3,4-dichlorophenyl)urea, Its English name is Triclocarban, CAS NO: 101-20-2, my country's "Journal of Nanchang University" (Engineering Edition), June 2002, the second issue of volume 24, pages 47-48, titled "N- (4-Chlorophenyl)-N'-(3,4-dichlorophenyl)urea New Synthesis Process Research", the proposed synthesis method is to synthesize 3,4-dichloronitrobenzene by nitration of o-dichlorobenzene , reduced to 3,4-dichloroaniline, and then reacted with p-chlorophenyl isocyanate; this synthesis method requires relatively clean p-chlorophenyl isocyanate, and the production of relatively pure p-chlorophenyl isocyanate has However, the energy consumption is high, the pollution is large,...

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Problems solved by technology

[0002] 3,4,4'-Trichlorophenylenediurea is an important daily chemical fungicide, its full name is N-(4-chlorophenyl)-N'-(3,4-dichlorophenyl)urea, Its English name is Triclocarban, CAS NO: 101-20-2, my country's "Journal of Nanchang University" (Engineering Edition), June 2002, the second issue of volume 24, pages 47-48, titled "N- (4-Chlorophenyl)-N'-(3,4-dichlorophenyl)urea New Synthesis Process Research", the proposed synthesis method is to synthesize 3,4-dichloronitrobenzene by nitration of o-dichlorobenzene , reduced to 3,4-dichloroaniline, and then reacted with p-chlorophenyl isocyanate; this synthesis method requires relatively clean p-chlorophenyl isocyanate, and the production of relatively pure p-chlorophenyl isocyanate has The energy consumption is high, the pollution is large, and the treatment is difficult. Especially in the rectification process in the later stage, the product is easy to coke and polymerize, and the yield is low; and in the above synthesis method, a large amount of organic solvents must be used

If reuse is not considered, the waste will be too large. If reuse, there will be too many impurities in the solvent, which will affect the purity, and it is difficult to remove by ordinary distillation.

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