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Preparation method of pirimicarb

A pirimicarb-resistant and dimethyl-resistant technology is applied to the preparation field of pirimicarb-resistant, can solve the problems of low yield, long reaction time and the like, and achieves the effects of short reaction time, low production cost, simple operation and post-processing

Active Publication Date: 2013-07-10
HUNAN HAILI CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Another main disadvantage of the reported dimethylcarbamoyl chloride method is that the reaction time is longer and the yield is not high.

Method used

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  • Preparation method of pirimicarb
  • Preparation method of pirimicarb
  • Preparation method of pirimicarb

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Add 34.1g (0.2mol) of 5,6-dimethyl-2-dimethylamino-4-hydroxypyrimidine (98%) into a 500mL three-necked flask with cooling tube, water separator, dropping funnel, thermometer, and stirring. 340g of toluene and 8.4g (0.2mol) of sodium hydroxide were stirred and heated to the reflux temperature, and the water generated by the reaction was removed from the system. After no obvious water was observed, the reflux was continued for 0.5hr (moisture content was less than 0.1% for sampling analysis). Cool down to 50°C, remove the water separator, add 0.3g of 4-dimethylaminopyridine and 24.1g (0.22mol) of dimethylcarbamoyl chloride into the kettle, stir and raise the temperature to 70°C for 3 hours, stop the reaction and cool down. Add 100mL of water to wash and separate the phases, and the organic phase is precipitated under negative pressure to obtain 47.8g. The content of pirimicarb is 98.6% according to the external standard method of liquid chromatography, and the yield is 99....

Embodiment 2

[0030] Add 34.1g (0.2mol) of 5,6-dimethyl-2-dimethylamino-4-hydroxypyrimidine (98%) into a 500mL three-necked flask with cooling tube, water separator, dropping funnel, thermometer, and stirring. 204.6g of toluene and 8.4g (0.2mol) of sodium hydroxide, stirred and heated to reflux temperature, removed the water generated by the reaction from the system, and continued to reflux for 0.5hr after no obvious water was produced (moisture content was less than 0.1% for sampling analysis) . Cool down to 50°C, remove the water separator, add 0.6g of 4-dimethylaminopyridine and 25.2g (0.23mol) of dimethylcarbamoyl chloride into the kettle, stir and raise the temperature to 70°C for 3 hours, stop the reaction and cool down. Add 100mL of water to wash and separate the phases, and the organic phase is precipitated under negative pressure to obtain 47.8g. The content of pirimicarb is 98.3% according to the external standard method of liquid chromatography, and the yield is 98.7%.

Embodiment 3

[0032] Add 34.1g (0.2mol) of 5,6-dimethyl-2-dimethylamino-4-hydroxypyrimidine (98%) into a 500mL three-necked flask with cooling tube, water separator, dropping funnel, thermometer, and stirring. 272.8g of toluene and 8.4g (0.2mol) of sodium hydroxide, stirred and heated to reflux temperature, removed the water generated by the reaction from the system, and continued to reflux for 0.5hr after observing that no obvious water was produced (moisture content was less than 0.1% in sampling analysis) . Cool down to 50°C, remove the water separator, add 0.9g of 4-dimethylaminopyridine and 28.5g (0.26mol) of dimethylcarbamoyl chloride into the kettle, stir and raise the temperature to 70°C for 2 hours, stop the reaction and cool down. Add 100mL of water to wash and separate the phases, and the organic phase is precipitated under negative pressure to obtain 47.9g. The content of pirimicarb is 98.8% according to the external standard method of liquid chromatography, and the yield is 99....

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Abstract

The invention discloses a preparation method of pirimicarb. The method is used for preparing the pirimicarb by reaction in which 5,6-dimentyl-2-dimethylamino-4-hydroxypyrimidine and dimethylamino carbamyl chloride are taken as raw materials, sodium hydroxide is taken as an acid-binding agent, an inert solvent, namely toluene or dimethylbenzene, is taken as a reaction solvent, and 4-dimethylamino pyridine is taken as a catalyst. The reaction formula is shown in the description, the pirimicarb content is as high as 98.1% to 99.2%, the reaction yield is as high as 98.1%-99.4% metered by 5,6-dimentyl-3-dimethylamino-4-hydroxypyrimidine, the reaction time is as short as 1h-3h, the acid-binding agent is unnecessary to recycle, the operation and subsequent processing are simple, and the production cost is low.

Description

technical field [0001] The invention relates to a preparation method of pirimicarb. Background technique [0002] Pirimicarb (5,6-dimethyl-2-dimethylamino-4-pyrimidinyl-dimethylcarbamate) is a selective aphidicide with contact, fumigation and foliar penetration , Molecular structure formula: [0003] [0004] Pirimicarb was developed by the British ICI company in 1965. There are mainly two methods for the synthesis of the original drug: phosgene and dimethylcarbamoyl chloride. [0005] There are many documents reporting the preparation method of pirimicarb. Document 1 uses benzene as solvent and reacts 5,6-dimethyl-2-dimethylamino-4-hydroxypyrimidine, triethylamine (acid-binding agent) with phosgene at low temperature , and then add an aqueous solution of dimethylamine to obtain the product by aminolysis at low temperature. The method has low reaction temperature and high speed. The disadvantage of this method is that the single-pass conversion rate is low, and 5,6-di...

Claims

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Application Information

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IPC IPC(8): C07D239/47A01N47/18A01P7/04
Inventor 毛春晖王宇庞怀林聂平王胜得陈明李利锋
Owner HUNAN HAILI CHEM IND
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