Synthesis method of tert-butyl isocyanate

A technology of tert-butyl isocyanate and butyl isocyanate, which is applied in the field of chemical synthesis, can solve problems such as difficulties in transportation and storage, hidden safety hazards, etc., and achieve the effects of reasonable process, safe production and low production cost

Inactive Publication Date: 2018-10-23
XINYI AGRI CHEM PLANT JIANGSU PROV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Because phosgene is a highly toxic gas, there are great potential safety hazards in laboratories, experiments or industrial production.
Although diphosgene is a liquid, it is easily decomposed into phosgene when it encounters activated carbon, iron or organic amines, and the transportation and storage process is relatively difficult, and there are also major safety hazards in the use process.

Method used

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  • Synthesis method of tert-butyl isocyanate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] In the 1000ml four-necked flask equipped with mechanical stirring, constant pressure dropping funnel, reflux condenser and thermometer, add the toluene of 2.4g triethylamine, 3.3 pyridine, 2.6g N-methylpyrrole and 249g to the four-necked flask, Start stirring and keep the stirring speed at 300 rpm, heat up to 90°C, add 135.5g of tert-butylcarbamoyl chloride, 27g of toluene, 0.3g of citric acid and 0.67g of p-toluenesulfonic acid into the constant pressure dropping funnel, at a temperature of 90°C Titrate for 3 hours, keep the reflux state at 90°C after the dropwise addition, continue to stir the reaction for 15 hours, and keep the stirring speed at 400 rpm. After the reaction is completed, send the mixed solution into a rotary evaporator. °C to 90 °C, washed with water three times, and dried in a vacuum oven at 80 °C for 9 hours to obtain 134.3 g of tert-butyl isocyanate with a yield of 92% and a content of 99.2%.

Embodiment 2

[0026] In a 1000ml four-necked flask equipped with mechanical stirring, a constant pressure dropping funnel, a reflux condenser and a thermometer, add 2.2g of triethylamine, 3.5g of pyridine, 2.8g of N-methylpyrrole and 2646g of dichlorobenzene, and start stirring And keep the stirring speed at 400 rev / min, heat up to 160°C, add 135.5g tert-butylcarbamoyl chloride, 294g dichlorobenzene, 0.54g citric acid and 0.98g p-toluenesulfonic acid into the constant pressure dropping funnel, at a temperature of 160°C Titrate for 2 hours, keep the reflux state at 160°C after the dropwise addition, continue to stir the reaction for 4 hours, and keep the stirring speed at 300 rpm. The temperature was 85°C, washed with water three times, and dried in a vacuum hollow drying oven at 90°C for 6 hours to obtain 135.8 g of tert-butyl isocyanate with a yield of 93% and a content of 99.5%.

Embodiment 3

[0028] In the 1000ml four-neck flask equipped with mechanical stirring, constant pressure dropping funnel, reflux condenser and thermometer, add 2.9g of triethylamine and 3.2g of pyridine, 2.3g of N-methylpyrrole and 1622g of chlorobenzene, start Stir and keep the stirring speed at 500 rpm, heat up to 110°C, add 135.5g of tert-butylcarbamoyl chloride, 180g of chlorobenzene, 0.76g of citric acid and 1.14g of p-toluenesulfonic acid into the constant pressure dropping funnel and add dropwise at 110°C 2h. After the dropwise addition, keep the reflux state at 110°C and continue to stir the reaction for 11h. Keep the stirring speed at 300 rpm. After the reaction is over, send the mixed solution to a rotary evaporator for rotary evaporation. at 90°C, washed with water three times, and dried at 70°C for 9 hours in a vacuum hollow oven to obtain 137.2 g of tert-butyl isocyanate with a yield of 94% and a content of 99.6%.

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Abstract

The invention relates to a synthesis method of tert-butyl isocyanate. The synthesis method comprises following steps: (1) evenly mixing a proper amount of catalyst and a solvent (90% of the theoretical amount) at a temperature of 90-180 DEG C to obtain a premixed solution, gradually dropwise adding a fed-batch solution into the premixed solution, after addition, maintaining the temperature of reaction solution in a range of 90-180 DEG C, keeping a reflux state, and carrying out reactions for 15 to 25 hours under stirring; and (2) after the reactions (1), delivering the mixed solution to a rotary evaporator, carrying out rotary evaporation, washing, and drying to obtain a tert-butyl isocyanate product. According to the synthesis method, tert-butyl amino formyl chloride directly carries outreactions in an inert solvent to prepare tert-butyl isocyanate; the safety hazard is radically inhibited from the source of the technology, and the preparation method has the advantages of reasonabletechnology, safety, high yield, and low production cost, and does not generate any wastewater, waste gas, or waste solid.

Description

technical field [0001] The invention relates to the field of chemical synthesis, in particular to a synthesis method of tert-butyl isocyanate. Background technique [0002] Tert-butyl isocyanate is an important intermediate in organic synthesis. The chemical synthesis method of tert-butyl isocyanate in the prior art is to synthesize tert-butylamine and highly toxic phosgene or diphosgene as raw materials. Because phosgene is a highly toxic gas, there is a greater potential safety hazard in laboratories, experiments or industrial production. Although diphosgene is a liquid, it is easily decomposed into phosgene when it encounters activated carbon, iron or organic amines, and the transportation and storage process is relatively difficult, and there is a greater safety hazard in the use process. Therefore, how to provide a safe and reliable method for synthesizing tert-butyl isocyanate is an urgent problem to be solved at present. Contents of the invention [0003] Aiming a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C263/04C07C265/04
CPCC07C263/04C07C265/04
Inventor 纪传武李国鹏佟林吴瑞磊
Owner XINYI AGRI CHEM PLANT JIANGSU PROV
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