Metamifop crystallization purification method

A technology of fenpyramid and purification method, which is applied in the field of chemical raw materials, can solve the problems of high energy consumption, high cost, and large product loss, and achieve the effects of saving purification process, removing impurities, and reducing loss

Inactive Publication Date: 2019-05-31
ANHUI THERAPY PHARMA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] The master thesis of Hunan Normal University "Study on the Synthesis of Mesifenzamide" also reported the use of a single solvent methanol for recrystallization, although the purity of 92% pure Mesifenzamide was crystallized. up to 99%, but this method is only applicable to the crystallization of oxamifamid with a higher purity. When recrystallizing the crude product of oxamfluzed with an impurity content greater than 20%, the product cannot be precipitated. This method is used for Secondary crystallization still forms a large amount of oil without crystals, and the content is less than 90%
[0007] CN99810369 and US2017215424A1 report the method of using column chromatography purification, but the cost of using column chromatography purification is very high, and the product obtained after purification is still a viscous oil, which is not conducive to industrial production; In the article "Research", it is reported that a single solvent methanol is used for recrystallization, but the product loss of this method is relatively large, and when recrystallization is carried out for the crude product of fenpyramid with an impurity content greater than

Method used

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Examples

Experimental program
Comparison scheme
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Example Embodiment

[0034] Example 1

[0035] Add 120g of crude oxadifen (content 79.6%) to a 1000mL reactor, then add 360g of isopropanol, heat and stir, control the temperature of the material at 80℃, stir for 1.5h to dissolve, after dissolving, heat to 0.5℃ Stir slowly at a cooling rate per minute to -5°C, keep for 1h, adjust the stirring speed to 45rpm, and slowly add 72g of water to the system at a uniform speed. The addition time should be longer than 1h. After the addition is complete, stir for 0.5h before adding 1.2 g oxadifen seed crystals, then stir for 0.5h, then continue to slowly add 144g of water to the reactor at a constant speed for 3h, after the addition, stir for 3h, filter, and rinse the filter cake twice with 72g of water, set Dry in an oven at 50°C to obtain a powdered solid of oxadifen. The purity is 99.57%, the content is 99.37%, and the crystallization yield is 98.67% by conventional methods. 1HNMR (400MHz, dmso-d6) δ 7.624-7.279 (m, 9H), 6.858-6.737 (m, 2H), 4.752-4.674 (m...

Example Embodiment

[0040] Example 2

[0041] Add 120g of crude oxadifen (content 79.6%) to a 1000mL reaction kettle, then add 460g of ethanol, heat and stir, control the temperature of the material at 50-70℃, stir for 1.5h to dissolve, after dissolving, heat to 0.5℃ Stir slowly at a cooling rate per minute to -3°C, keep for 1h, adjust the stirring speed to 45rpm, and add 72g of water to the system slowly and uniformly. The addition time should be longer than 1h. After the addition is complete, stir for 0.5h and then add 1.2 g oxadifen seed crystals, then stir for 0.5h, then continue to slowly add 144g of water to the reactor at a constant speed for 3h, after the addition, stir for 3h, filter, and rinse the filter cake twice with 72g of water, set Dry in an oven at 45°C to obtain a powdered solid of oxadifen. The purity is 99.13%, the content is 99.26%, and the crystallization yield is 95.37% by conventional methods.

Example Embodiment

[0042] Example 3

[0043] Add 120g of crude oxadifen (content 79.6%) to a 1000mL reactor, then add 360g of methanol, heat and stir, control the temperature of the material at 50-60℃, stir for 1.5h to dissolve, after dissolving, heat to 0.5℃ Stir slowly at a cooling rate per minute to -5°C, keep for 1h, adjust the stirring speed to 45rpm, and slowly add 72g of water to the system at a uniform speed. The addition time should be longer than 1h. After the addition is complete, stir for 0.5h before adding 1.2 g oxfenacet seed crystals, and then stir for 0.5h, then continue to slowly add 144g of water to the reactor at a constant speed for 3h, after the addition, stir for 3h, filter, and rinse the filter cake twice with 72g water, set Dry in an oven at 55°C to obtain oxadifen in powder form. By conventional methods, the purity is 99.42%, the content is 99.35%, and the crystallization yield is 97.34%.

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Abstract

The invention discloses a metamifop crystallization purification method which includes the steps: (1) dissolving metamifop crude products in solvents A, increasing temperature to reach 40-90 DEG C andstirring solution for 0.5-2 hours; (2) slowly reducing the system temperature to range from -10 DEG C to 10 DEG C and keeping the temperature for 0-1 hour; (3) adjusting stirring speed to be higher than 30rpm and slowly adding solvents B; (4) adding 0.5%-5% of metamifop seed crystals; (5) continuing slowly adding the solvents B and stirring the solution for 1-5 hours; (6) performing suction filtration, flushing filter cakes by an appropriate quantity of solvents B, drying the filter cakes after flushing, and controlling the temperature of a drying oven to range from 30 DEG C to 60 DEG C to obtain high-content metamifop crystals after drying. The content of the metamifop crystals can reach 99% or more, the method is less in loss, low in cost and suitable for industrial production, and solvent recovery is facilitated.

Description

Technical field: [0001] The invention relates to the related technical field of chemical raw materials, in particular to a method for crystallization and purification of fenpyramid. Background technique: [0002] Methafen is an aryloxyphenoxypropionate herbicide with the chemical name (2R)-2-[4-[(6-chloro-2-benzoxazolyl)]phenoxy] -N-(2-fluorophenyl)-N-methylpropanamide. Because of its low toxicity, environmental protection and rice safety, it has a broad market prospect. Its structure is shown in the following formula: [0003] [0004] In the reported synthetic methods of fenpyramid, most of the obtained fenfenpyr products are oily crude products. However, there are very few reports on the crystallization and purification of the crude product of fenpyramid. [0005] A method of recrystallization using methanol was reported in the article "Study on the Synthesis of Methazone" in the Eleventh National Pesticide Exchange Conference. After using this method to recrystal...

Claims

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Application Information

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IPC IPC(8): C07D263/58
Inventor 任磊彭兵兵孙玉行张红夺柏林张文龙
Owner ANHUI THERAPY PHARMA CO LTD
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