Preparation method of p-toluenesulfonyl isocyanate

A technology of toluenesulfonyl isocyanate and p-toluenesulfonamide is applied in the field of preparation of p-toluenesulfonyl isocyanate, can solve the problems of poor production safety and high equipment requirements, and achieves high recycling rate, high safety and high product yield Effect

Inactive Publication Date: 2022-03-15
SHOUGUANG NUOMENG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, the domestic production process is mostly prepared by p-toluenesulfonamide and phosgene under high pressure and high temperature. This preparation method requires high equipment requirements, and there is a highly toxic raw material phosgene, which has poor production safety.

Method used

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  • Preparation method of p-toluenesulfonyl isocyanate
  • Preparation method of p-toluenesulfonyl isocyanate
  • Preparation method of p-toluenesulfonyl isocyanate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Add 47.76g of dimethyl carbonate (content 99%, 0.525mol) into a 500ml four-pin bottle, stir and pass in 228.14g of chlorine gas (content 99.9%, 3.21 mol, dimethyl carbonate: chlorine = 1:6.11), slowly pass With the reaction, the temperature gradually increased, adding a water bath, controlling the temperature to 30°C, and the chlorine passing time was about 8 hours to complete.

[0029] Stir and dissolve 86.04g p-toluenesulfonamide (content 99.5%, 0.5mol, p-toluenesulfonamide: dimethyl carbonate = 1:1.05) and 86g chlorobenzene, and add it to a constant pressure dropping funnel.

[0030] After the chlorine reaction is completed, add the p-toluenesulfonamide chlorobenzene solution into the four-necked bottle, stir and raise the temperature to above 90°C, control the temperature at 90°C and react for 4 hours, take a sample to detect the complete reaction of the raw materials, connect the condenser tube and the receiving bottle, and start recovery The solvent is chlorobenze...

Embodiment 2

[0033] Add 45.49g of dimethyl carbonate (content 99%, 0.5mol) into a 500ml four-pin bottle, stir and pass in 234.53g of chlorine gas (content 99.9%, 3.3mol, dimethyl carbonate: chlorine = 1:6.6), slowly pass With the reaction, the temperature gradually increased, adding a water bath, controlling the temperature to 40°C, and the chlorine passing time was about 8 hours to complete.

[0034] Stir and dissolve 86.04g p-toluenesulfonamide (content 99.5%, 0.5mol, p-toluenesulfonamide: dimethyl carbonate = 1:1) and 86g chlorobenzene, and add it to a constant pressure dropping funnel.

[0035] After the chlorine reaction is completed, add the p-toluenesulfonamide chlorobenzene solution into the four-necked bottle, stir and raise the temperature to above 90°C, control the temperature at 100°C for 4 hours, take a sample to check that the raw material has reacted completely, connect the condenser tube and the receiving bottle, and start recovery The solvent is chlorobenzene, the vacuum d...

Embodiment 3

[0038] Add 50.04g of dimethyl carbonate (content 99%, 0.55mol) into a 500ml four-pin bottle, stir and pass in 232.53g of chlorine gas (content 99.9%, 3.3mol, dimethyl carbonate: chlorine = 1:6), slowly pass With the reaction, the temperature is gradually increased, add a water bath, control the temperature at 50°C, and complete the chlorine passage in about 8 hours.

[0039] Stir and dissolve 86.04g p-toluenesulfonamide (content 99.5%, 0.5mol, p-toluenesulfonamide: dimethyl carbonate = 1:1.1) and 86g chlorobenzene, and add to the constant pressure dropping funnel.

[0040] After the chlorine reaction is completed, add the p-toluenesulfonamide chlorobenzene solution into the four-necked bottle, stir and heat up to above 90°C, control the temperature at 105°C for 4 hours, take a sample to check that the raw material has reacted completely, connect the condenser tube and the receiving bottle, and start recovery The solvent is chlorobenzene, the vacuum degree is controlled at -0.0...

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Abstract

The invention belongs to the technical field of chemical production, and particularly relates to a preparation method of p-toluenesulfonyl isocyanate, which comprises the following steps: (1) chlorination reaction: adding dimethyl carbonate into a reaction kettle, and introducing chlorine; (2) esterification reaction: adding a p-toluene sulfonamide chlorobenzene solution into the reaction kettle, and refluxing at 90-110 DEG C; and (3) refining: after the esterification reaction is completed, carrying out reduced pressure recovery of chlorobenzene from a reactant, and carrying out high vacuum distillation on the reactant from which the chlorobenzene is recovered, so as to obtain p-toluenesulfonyl isocyanate. The adopted raw materials do not contain phosgene and are high in safety, synthesis requirements can be met without high-pressure reaction equipment, the reaction is carried out in an almost anhydrous environment, p-toluenesulfonyl isocyanate is prevented from being subjected to a hydrolysis reaction, the product yield reaches 95% or above, a distillation method is adopted for refining, and the product purity can reach 98% or above; the reaction solvent is high in recycling rate and almost has no process wastewater.

Description

technical field [0001] The invention belongs to the technical field of chemical production, in particular to a preparation method of p-toluenesulfonyl isocyanate. Background technique [0002] P-toluenesulfonyl isocyanate is an important organic chemical intermediate, mainly used as a pharmaceutical intermediate for the synthesis of hypoglycemic drugs glimepiride, gliclazide, glipizide, etc., for the treatment of type Ⅱ diabetes. In the field of pesticides, it can be used to synthesize sulfonylurea herbicides, etc. [0003] At present, the domestic production process mostly uses p-toluenesulfonamide and phosgene to be prepared under high pressure and high temperature conditions. This preparation method requires high equipment requirements, and there is a highly toxic raw material phosgene, which has poor production safety. Contents of the invention [0004] The object of the present invention is to provide a kind of safety, need not high pressure, the preparation method o...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C303/40C07C303/44C07C311/65C07C68/06C07C69/96
CPCC07C303/40C07C303/44C07C68/06C07C69/96C07C311/65
Inventor 李庆山胡新河刘在成张光
Owner SHOUGUANG NUOMENG CHEM
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