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Method for preparing precursor of cycloprothrin

A technology for cypermethrin and a precursor is applied in the field of preparing cypermethrin precursor, which can solve the problems of long process route, difficult purification, low yield and the like, and achieves optimization of reaction conditions, improvement of reaction yield and good thermal effect. Effect

Inactive Publication Date: 2006-02-15
SHANGHAI INST OF ORGANIC CHEMISTRY - CHINESE ACAD OF SCI +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The above process route is long, the yield is low, and most of the intermediates are oily liquids with high boiling points, which need to be purified by high vacuum distillation, which is difficult to purify, resulting in high cost

Method used

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  • Method for preparing precursor of cycloprothrin
  • Method for preparing precursor of cycloprothrin
  • Method for preparing precursor of cycloprothrin

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] Add 40 grams of phenetole and 40 grams of ethyl pyruvate to 400 milliliters of dichloromethane, then add 31 grams of aluminum oxide, then cool the system to minus 45 degrees, start adding titanium tetrachloride, and keep the temperature from minus 45 to minus 20 degrees, and then react at this temperature. Gas chromatographic tracking until the reaction raw materials no longer decreased. React between minus 10 degrees and 5 degrees. After the reaction is complete, add the reaction mixture into stirred water at 0-5 degrees to quench the reaction. The extract was concentrated and evaporated under reduced pressure to remove the solvent to obtain 43 g of the product aryl lactate, with a yield of 55%. Compound Characterization Data:

[0036]

[0037] FTIR (neat): 3506, 2983, 1728, 1247cm -1 ; 1 H NMR (CDCl 3 , 300MHz) δ=7.46(d, J=9.0Hz, 2H), 6.87(d, J=8.7Hz, 2H), 4.25(q, J=7.1Hz, 2H), 4.02(q, J=7.0Hz, 2H), 3.77(s, 3H), 3.72(s, 1H), 1.75(s, 3H), 1.41(t, J=7.0Hz, 3H),...

Embodiment 2

[0039] Add 40 grams of phenetole and 40 grams of methyl pyruvate to 400 milliliters of dichloromethane, then add 31 grams of barium oxide, then cool the system to minus 45 degrees, start adding titanium tetrachloride, and keep the temperature from minus 45 to minus 20 degrees, and then react at this temperature. Gas chromatographic tracking until the reaction raw materials no longer decreased. React between minus 10 degrees and 5 degrees. After the reaction is complete, add the reaction mixture into stirred water at 0-5 degrees to quench the reaction. The extract was concentrated and evaporated under reduced pressure to remove the solvent to obtain 41 g of the product aryl lactate, with a yield of 51%.

[0040]

[0041] FTIR (neat): 3523, 2983, 1721, 1245cm -1 ; 1 H NMR (CDCl 3 , 300MHz) δ=7.45(d, J=9.0Hz, 2H), 6.87(d, J=8.7Hz, 2H), 4.02(q, J=7.0Hz, 2H), 3.76(s, 3H), 3.72( s, 1H), 1.76(s, 3H), 1.41(t, J=7.0Hz, 3H); 13 C NMR (CDCl 3 , 75MHz) δ=176.2, 158.4, 134.5, 126...

Embodiment 3

[0043]500 grams of 4-ethoxyphenyl ethyl lactate was added to 2000 milliliters of chloroform, then 2.5 grams of hydroquinone and 20 grams of p-toluenesulfonic acid were added, the water was separated under reflux, and the gas phase followed the reaction until the raw material was less than 1%. A total of 1000 ml of chloroform was distilled off. Cool, wash twice with 400 ml of 10% sodium hydroxide, and then add 3.6 g of benzyltriethylammonium chloride. The system was heated to 55 degrees, and 1800 grams of 50% sodium hydroxide aqueous solution was added dropwise, and the temperature was controlled at 50-65 degrees. The reaction during the dropwise addition was very violent and difficult to control. There have been three occurrences of flushing. If the dropwise addition is too slow, there will be saponification of the raw material acrylate. After adding, keep warm between 50-60 degrees until the raw material is less than 1%. Add 2000 ml of dichloroethane, separate the phases,...

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Abstract

The invention provides a process for synthesizing cycloprothrin, which comprises using 4-ethoxy phenyl lactate as key intermediate, carrying out dehydration under acidic condition to obtain methyl acrylate, subjecting 2-(4-ethoxy phenyl)methyl acrylate to dichlorocarbene reaction, obtaining three-membered ring of dichlorocarbene, saponifying into acid and carrying out acylation, reacting with cyanohydrin to obtain the cycloprothrin.

Description

Technical field: [0001] The invention relates to a new process for promethrin precursor. Background technique: [0002] Cycloprothrin is a synthetic pyrethroid insecticide that is low-toxic to fish and other aquatic organisms and can be used in paddy fields. Its structural formula is as follows: [0003] [0004] The literature synthesis method is to start from p-hydroxyphenylacetic acid, obtain ethyl p-ethoxyphenylacetate through etherification and esterification, then condense with formaldehyde to obtain 2-(p-ethoxyphenyl) acrylate, and then react with dichloro The carbene is reacted to form a three-membered ring, then saponified into an acid, and finally made into an acyl chloride and then reacted with cyanohydrin to obtain promethrin. The route is as follows: [0005] [0006] The above process route is long, the yield is low, and most of the intermediates are oily liquids with high boiling points, which need to be purified by high vacuum distillation, which is di...

Claims

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Application Information

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IPC IPC(8): C07C69/757C07C67/30
CPCC07C67/327C07C67/343C07C67/347
Inventor 姜标司玉贵陈君李凡李金华秦叶军
Owner SHANGHAI INST OF ORGANIC CHEMISTRY - CHINESE ACAD OF SCI