Production control method of 98 percent carbofuran

A production control method and content technology, applied in organic chemistry and other directions, can solve the problems of increasing recrystallization operations and costs, and achieve the effects of avoiding recrystallization operations, less solvent recovery, and low energy consumption

Active Publication Date: 2012-10-17
HUNAN HAILI CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0011] CN98112498 discloses a method for refining carbofuran, which uses binary solvents such as alcohol / water to recrystallize the crude product to obtain high-content carbofuran. This method needs to increase the recrystallization operation and cost

Method used

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  • Production control method of 98 percent carbofuran
  • Production control method of 98 percent carbofuran
  • Production control method of 98 percent carbofuran

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Add 66g of industrial furanol (99%), 264g of 1,2-dichloroethane and 0.4g of triethylamine into a 500mL three-necked flask with cooling tube, dropping funnel, thermometer, and stirring, and heat to reflux temperature to start adding methyl Isocyanate, add 0.42mol methyl isocyanate within 1 hour, cool and crystallize at the end of the reaction, centrifuge filter and wash the filter cake with 20g of 1,2-dichloroethane, and the dry weight of the filter cake is 68.3g, analyzed by liquid chromatography external standard method The mass content of Weiwei is 98.9%.

[0029] The weight of the filtrate was 285.7g. Weighed out 10% of the filtrate and added fresh 1,2-dichloroethane of the same quality. The mixed filtrate was recycled as the solution for the next batch of reactions. The weighed 10% filtrate was distilled to recover 24.5g of 1,2-dichloroethane and 2.1g of white solid (carbofuran mass content 90.8%).

Embodiment 2

[0031] Applicable experiment: Add 66g of industrial product furanol (99%) and all the mother liquor of Example 1 into a 500mL three-neck flask with cooling tube, dropping funnel, thermometer, and stirring, and heat to reflux temperature to start adding methyl isocyanate dropwise. After adding 0.42 mol of methyl isocyanate, continue the reaction at 80°C for 1 hour. After the reaction is completed, cool and crystallize, filter the filter cake with 20 g of fresh 1,2-dichloroethane, dry the filter cake, and treat the filtrate according to the method of Example 1. , the experimental results are shown in Table 2.

[0032] Table 2 Applied experimental results

[0033] the batch

[0034] Apply 4 times

Embodiment 3

[0036] Add 66g of industrial furanol (99%), 132g of 1,2-dichloroethane and 0.4g of triethylamine into a 500mL three-necked flask with cooling tube, dropping funnel, thermometer, and stirring, and heat to reflux temperature to start adding methyl Isocyanate, add 0.42mol methyl isocyanate within 1 hour, cool and crystallize at the end of the reaction, centrifuge filter and wash the filter cake with 20g of 1,2-dichloroethane, and the dry weight of the filter cake is 78.8g, analyzed by liquid chromatography external standard method Granite mass content 98.4%.

[0037] The weight of the filtrate was 143.6g. Weighed out 15% of the filtrate and added fresh 1,2-dichloroethane of the same quality. The mixed filtrate was recycled as the solution for the next batch of reactions. The weighed 15% filtrate was distilled to recover 19.1g of 1,2-dichloroethane and 1.6g of white solid (mass content of carbofuran: 87.0%).

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Abstract

The invention provides a production control method of 98 percent carbofuran. The method comprises the following steps: reacting by adopting 1,2-dichloroethane or 1,2-dichloropropane as a reacting and crystallizing solvent, wherein the usage of the solvent is 2 to 4 times that of the mass of furan phenol, and the molar ratio of the furan phenol to methyl isocyanate to triethylamine is 1:1.05-0.01; dripping methyl isocyanate at a refluxing temperature; cooling, crystallizing and filtering after the reaction; drying the filter cake to obtain a main product with mass content of between 98.0 and 98.9 percent; adding a new solvent with the same mass when 10 to 15 percent of the mass of the filtrate is separated every time, and combining to be used as a mother liquor for next reaction; and distilling the filtrate which is separated in each time, using the recycled solvent as a fresh solvent, and thus obtaining the carbofuran side product with the mass content of between 84.1 and 92.7 percent, wherein the total yield is 99.0 to 99.8 percent in furan phenol. According to the production control method, recrystallization operation can be avoided, the mass content of the main product carbofuran can be stably controlled to be between 98.0 and 98.9 percent, and the solvent recycling amount is small; the side produced carbofuran product with mass content of between 84.1 and 92.7 percent can be used as a raw material of 3 percent carbofuran granules.

Description

technical field [0001] The invention relates to a production control method of 98% carbofuran. Background technique [0002] Carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuryl methylcarbamate) is a broad-spectrum insecticide and nematocide, molecular structure formula: [0003] [0004] It is suitable for the control of various pests on rice, cotton, tobacco, soybean and other crops, and can also be specially used as a seed treatment agent. [0005] US5387702 discloses a preparation method of carbofuran, which adopts aprotic solvents such as benzene or toluene, reacts furan phenol with methyl isocyanate in the presence of trimethylamine or triethylamine catalyst, filters and dries to obtain carbofuran, and the yield is 95%. . [0006] [0007] GB1265255 discloses a preparation method of carbofuran, which uses benzene, cyclohexane, methylcyclohexane, heptane, hexane, dichloromethane, chloroform, carbon tetrachloride or methyl isobutyl Ether and other solvents, in the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D307/86
Inventor 王晓光王宇庞怀林毛春晖臧阳陵李萍陈明
Owner HUNAN HAILI CHEM IND
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