Chemical synthesis method of 3,4-dichlorobenzene isocyanate

A technology for chemical synthesis of dichlorobenzene isocyanate, applied in the fields of pesticides, dyes, and synthetic medicines, can solve the problems of serious equipment corrosion, long reaction period, and large safety hazards, and achieves small equipment corrosion, low production cost, and safe and reliable production. Effect

Inactive Publication Date: 2004-03-03
蔡戈冬
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of this process is that it uses phosgene, a highly toxic raw material that is restricted in the world, which has great safety hazards, and the reaction cycle is long, and the equipment is severely corroded. The most troublesome thing is that the amount of three wastes is large, and the treatment is difficult and expensive
In production, there must be an additional set of equipment for producing and storing phosgene; if phosgene leaks, it will bring great problems to environmental pollution

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] 3,4-dichloroaniline: bis(trichloromethyl) carbonate: 1,3-dimethyl-2-imidazolidinone=1:0.35:0.01 (molar ratio), the amount of toluene is 3,4-di 10 times the mass of chloroaniline.

[0014] First, add 3,4-dichloroaniline, 1,3-dimethyl-2-imidazolidinone and toluene into the reaction kettle, start stirring, after stirring evenly, add bis(trichlorohydrin) dropwise within 1 hour at room temperature Toluene solution of methyl)carbonate, and then heated up and refluxed for 4 hours. After the reaction, the toluene was recovered by distillation under reduced pressure. Finally, the fraction at 120-122°C was collected at 2.6Kpa, solidified after cooling, with a melting point of 42-43°C and a content of 99.2 %, yield 95.2%.

Embodiment 2

[0016] 3,4-dichloroaniline: bis(trichloromethyl) carbonate: 1,3-dimethyl-2-imidazolidinone=1:0.35:0.005 (molar ratio), the amount of reclaimed toluene is 3,4- 10 times the mass of dichloroaniline. According to the operation of Example 1, the final product obtained has a melting point of 42-43° C., a content of 99.5%, and a yield of 96.0%.

Embodiment 3

[0018] 3,4-dichloroaniline: bis(trichloromethyl) carbonate: 1,3-dimethyl-2-imidazolidinone=1:0.5:0.01 (molar ratio), the amount of toluene is 3,4-di 10 times the mass of chloroaniline.

[0019] According to the operation of Example 1, the final product has a melting point of 41-43° C., a content of 99.0%, and a yield of 96.5%.

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PUM

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Abstract

A process for chemically synthesizing 3,4-dichlorobenzene isocyanate includes such steps as proportionally mixing 3,4-dichlorophenylamine, catalyst and organic solvent to reactor, stirring, dripping the solution of bicarbonate in organic solvent into the solution, reacting at 20-180 deg.C for 3-10 hr, vacuum distilling to recover organic solvent, collecting fraction, cooling and solidifying. Its advantages are high output rate, low cost and less corrosion to equipment.

Description

technical field [0001] The invention relates to the field of synthetic medicine, pesticide and dye, and mainly relates to a chemical synthesis method of 3,4-dichlorophenylisocyanate. Background technique [0002] 3,4-Dichlorophenylisocyanate is an important intermediate of medicine, pesticide and polymer material. The traditional chemical synthesis method of 3,4-dichlorophenylisocyanate is prepared by reacting phosgene and 3,4-dichloroaniline as raw materials, and this method is also mainly used in industrial production at present. The disadvantage of this process is that it uses phosgene, a highly toxic raw material that is restricted in the world, which has great potential safety hazards, and the reaction cycle is long, and the equipment is seriously corroded. The most troublesome thing is that the amount of three wastes is large, and the treatment is difficult and expensive. In production, there must be an additional set of equipment for producing a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C263/00C07C265/12
Inventor 蔡戈冬曹国君王波华
Owner 蔡戈冬
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