Method for preparing (Z)-N-hydroxyphenylamidine by ammonolysis method

A technology of hydroxybenzamidine and solution method, which is applied in the field of preparation of -N-hydroxybenzamidine by ammonolysis method, can solve the problems of difficult separation, low yield, difficult separation, etc., and achieve the effect of improving the conversion rate

Active Publication Date: 2021-01-05
HUNAN JINGSHI NEW MATERIAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0016] The purpose of the present invention is to solve the problems of many by-products, difficult separation, low yield and other problems in the preparation method of (Z)-N-hy...

Method used

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  • Method for preparing (Z)-N-hydroxyphenylamidine by ammonolysis method
  • Method for preparing (Z)-N-hydroxyphenylamidine by ammonolysis method
  • Method for preparing (Z)-N-hydroxyphenylamidine by ammonolysis method

Examples

Experimental program
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Effect test

Embodiment 1

[0062] (Z)-N-hydroxyl-2,3-difluoro-5-trifluoromethylphenylamidine was prepared by ammonolysis, and the reaction equation was as follows:

[0063]

[0064] Take 51.9g (0.2mol) of α-chloro-2,3-difluoro-5-trifluoromethylbenzaldehyde oxime (E, Z configuration mixture) and dissolve it in 250ml of absolute ethanol, then add 1.66g (0.006mol) of the anhydrous potassium salt of 2,3-difluoro-5-trifluoromethylbenzohydroxamic acid, keep warm at 0-5°C and stir for 24 hours, then heat up to 20-30°C, and stir in batches A total of 15.8 g (0.2 mol) of ammonium bicarbonate was added; after the addition was complete, the reaction was still stirred at 20-30° C. for 24 hours. Concentrate under reduced pressure with a rotary evaporator to remove most of the ethanol, add 200 g of water and 200 g of chloroform to the concentrated residue, and stir at 30-40° C. until most of the solids are dissolved. Filtrate while it is hot, and the obtained filter cake is the potassium salt of 2,3-difluoro-5-tr...

Embodiment 2

[0074] Adopt ammonolysis method to prepare (Z)-N-hydroxyl-4-trans-(4-ethyl)cyclohexylphenylamidine, and the reaction equation is as follows:

[0075]

[0076] In a 1000ml autoclave, mix 62.0g (0.2mol) of α-bromo-4-trans-(4-ethyl)cyclohexylbenzaldehyde oxime (E, Z configuration mixture) with 200ml of anhydrous isopropyl Alcohol and 100ml of toluene were mixed, then 3.18g (0.02mol) of anhydrous sodium salt of benzohydroxamic acid was added, and the mixture was kept at 55-60°C and stirred for 1 hour. Then add an ammonia gas ethanol solution containing a total of 6.8 g of ammonia (0.4 mol), seal the autoclave, heat up to 90-100° C. under stirring and react for another hour. Then cool down to below 40°C, take out the reaction mixture, concentrate under reduced pressure with a rotary evaporator to remove most of the isopropanol, add 200g of water and 200ml of toluene to the concentrated residue, and stir at 30-40°C until most of the solids dissolve. Filtration, the obtained fil...

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Abstract

The invention discloses a method for preparing(Z)-N-hydroxyphenylamidine by ammonolysis, which comprises the following steps: 1, completely or partially dissolving alpha-halogenated benzaldoxime compounds simultaneously containing E and Z two configurations by using a first solvent to obtain a solution A; 2, adding an anhydrous sodium salt or potassium salt of a benzohydroxamic acid compound, andstirring to fully convert the (E)-alpha-halogenated benzaldoxime compound into (Z) type to obtain a solution B; 3, adding an anhydrous ammonia source, and carrying out an ammonolysis reaction to generate (Z)-N-hydroxybenzamidine so as to obtain a solution C; 4, concentrating the solution C, and adding water and a second solvent to dissolve most of solids; filtering and separating liquid; and carrying out post-treatment to obtain the high-purity (Z)-N-hydroxyphenylamidine. According to the method disclosed by the invention, the E configuration in the raw material can be fully converted into theZ configuration, the problem that more alkaline hydrolysis side reactions occur during E and Z configuration conversion reaction and ammonolysis reaction is also avoided, and the yield of the purified target product is increased to 95% or above.

Description

technical field [0001] The invention belongs to the field of medicine and chemical industry, and relates to a method for preparing (Z)-N-hydroxybenzamidine by ammonolysis. Background technique [0002] N-Hydroxybenzamidine compounds are a class of intermediates widely used in medicine, pesticides, organic materials, and organic fine chemical industries; this type of compound has two isomers of E and Z configurations, and its molecular structure is The general formula is as follows: [0003] [0004] R in the above general formula is various common substituents on the benzene ring, such as aliphatic group, aromatic group, halogen, ester group, amino group, nitro group, cyano group, or their combination groups, etc. (hereinafter the same ). [0005] N-hydroxybenzamidine compounds are the most commonly used and one of the cheapest preparation methods, which is to carry out ammonolysis reaction with α-halogenated benzaldoxime compounds; and this ammonolysis reaction is used...

Claims

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Application Information

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IPC IPC(8): C07C259/18
CPCC07C259/18Y02P20/55
Inventor 屈东东周维江宋斌
Owner HUNAN JINGSHI NEW MATERIAL CO LTD
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