Method for preparing dexiotropous antifoim dichlor chrysanthemic acid in high optical purity through method of induced crystallization

A technology of optical purity and diclofenac, applied in the field of preparation of chiral diclofenac, can solve the problems of complicated process flow and high price of resolving agent

Inactive Publication Date: 2004-03-10
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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Problems solved by technology

With the method of chemical resolution, although R(+)-trans-permethrin with an optical purity of mor

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Get 1.0 g of chiral permethrin with considerable optical purity (Chinese Patent Application No. 00110029.7 (2000.1.12)) obtained by kinetic resolution of pig liver esterase, and its four isomers are composed of: S(-) -cis-body 0.23%, R(+)-cis-body 0.43%, S(-)-trans-body 10.15%, R(+)-trans-body 89.19%, dissolved in warm petroleum ether to form over After the solution is saturated, a small amount (the added amount is 1 / 10,000 of the weight of chiral permethrin) fine sucrose crystals are added as induced seed crystals, and slowly crystallized at room temperature (10-20° C.). After derivatization with chiral menthol after drying, the composition of the four isomers was determined by gas chromatography (10% QF-1 column, 5m, hydrogen flame detector): S(-)-cis-body 0.24% , R(+)cis-body 0.84%, S(-)-trans-body 2.21%, R(+)-trans-body 96.72%, yield 75.0%, R(+)-trans-permethrin The optical purity increased from 89.19% to 96.72%, an increase of 7.53%.

Embodiment 2

[0019] Take 1.0 g of chiral permethrin with considerable optical purity obtained by enzymatic kinetic resolution, and its isomer composition is: S(-)-trans-body 13.56%, R(+)-trans-body 86.44% %, dissolved in warm ether to form a supersaturated solution, add a small amount (the amount added is one thousandth of the weight of chiral permethrin) fine dextran crystals, place it at room temperature for slow crystallization, and use it after drying The gas chromatographic method described in Example 1 determines that the isomer composition is: S(-)-cis-body 0, R(+)-cis-body 0.51%, S(-)-trans-body 3.84%, R(+ )-trans-isomer 95.65%, yield 77.2%, the optical purity of R(+)-trans-permethrin increased from 86.44% to 95.65%, an increase of 9.21%.

Embodiment 3

[0021] Take 1.0 g of chiral permethrin with considerable optical purity obtained by enzymatic kinetic resolution, and its isomer composition is: S(-)-trans-body 11.76%, R(+)-trans-body 88.24% %, dissolved with warm cyclohexane to form a supersaturated solution, then add a small amount of fine sodium glutamate crystals as induced seed crystals, and slowly crystallize at room temperature (10-20°C). After drying, according to the method described in Example 1, the composition of the four isomers was measured: S(-)-trans-body 3.92%, R(+)-trans-body 97.08%, yield 72.0%, R( The optical purity of +)-trans-permethrin increased from 88.24% to 97.08%, an increase of 8.84%.

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Abstract

A process for preparing high-optical-purity R(+)-trans-dichlorochrysanthemic acid by induced crystallizing method includes dissolving chiral dichlorochrysanthemic acid in hot solvent to become supersaturated solution, adding the inducing crystal seeds, slow natural crystallizing, drying and testing its 4 isomers by gas-phase chromatography. Its advantage is high optical purity increased by 5-10%.

Description

technical field [0001] The invention relates to a preparation method of chiral permethrin, in particular to a method for preparing high optical purity R(+)-trans-permethrin by adding a specific seed crystal recrystallization method. Background technique [0002] Permethrin as a pyrethroid pesticide intermediate has a chemical formula as follows: [0003] It has four isomers, namely S(-)-cis-body (left-handed cis), R(+)cis-body (right-handed cis), S(-)-trans-body (left-handed trans) , R(+)-trans-body (dextrotrans). Among them, the R(+)-trans body is the object. In order to adapt to the development trend of synthesizing high-efficiency, low-toxicity and environment-friendly chiral pesticides, the higher the optical activity, the better. In order to further improve the optical purity of the R(+)-trans-permethrin obtained by the enzyme kinetic resolution method, if a highly efficient and specific biocatalyst (bacteria or enzyme) is screened or a genetic engineering method i...

Claims

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Application Information

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IPC IPC(8): C07C51/43C07C61/37
Inventor 邵昌平刘韧白长敏韩梅郑卓
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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