Unlock instant, AI-driven research and patent intelligence for your innovation.

Green method for preparing chloroacetaldehyde dialkyl alcohol from vinyl acetate

A technology of chloroacetal dialkyl acetal and chloroacetal dimethyl acetal is applied in the field of organic chemistry and pharmaceutical intermediates, and can solve the problems of long process route of indirect method, difficulty in recycling and reuse, and many side reactions of chlorination. , to achieve the effect of simple operation, easy recycling and good benefits

Inactive Publication Date: 2020-12-08
石家庄欧特佳化工有限公司
View PDF10 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The indirect method has a long process route and poor economy. It is often necessary to add a large amount of calcium chloride to absorb the water in chloroacetaldehyde. Due to the strong water solubility of methanol and the strong complexing ability with calcium chloride, water, methanol and calcium chloride are formed. Complex mixtures, recycling is very difficult
The direct method is currently mainly chlorinating vinyl acetate in methanol. Although this method avoids the introduction of water to a large extent, there are many side reactions in the chlorination of methanol

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Green method for preparing chloroacetaldehyde dialkyl alcohol from vinyl acetate
  • Green method for preparing chloroacetaldehyde dialkyl alcohol from vinyl acetate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] (1) Chlorination: Add 860 g of vinyl acetate, 8.6 g of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, and 8.6 g of benzyltriphenylphosphine chloride into a 2L three-necked flask ; Protect from light and stir, control 15-20 ° C, and pass 710g of chlorine gas for 4 hours.

[0025] (2) Alcoholysis: drop the chlorinated solution into 1280g of methanol, and control the temperature of the water bath to not exceed 50°C; after 1 hour of dripping, remove the water bath, and continue to stir at 45-50°C for 2 hours.

[0026] (3) Neutralization: the alcoholysis solution is cooled to 8°C, the temperature of the ice-water bath is not more than 10°C, and 850g of 20% ammonia water is dripped until the pH value of the reaction solution reaches 8; the ammonium chloride generated is filtered and dried to obtain chlorine Ammonium chloride 480g.

[0027] (4) Liquid separation: the filtrate separates the lower organic phase, and the organic phase is washed with an aqueous solution of ...

Embodiment 2

[0030] (1) Chlorination: Add 860g of vinyl acetate, 8.6g of 2,6-di-tert-butyl-4-methylbenzoic acid and 8.6g of benzyltriethylammonium chloride into a 2L three-necked flask, keep away from light and stir Under the control of 15-20°C, 710g of chlorine gas was passed through for 4 hours.

[0031] (2) Alcoholysis: Add the chlorinated solution to 1200g of methanol and add 80g of the transition fraction in Example 1, and control the temperature in the water bath to not exceed 50°C; after 1 hour of dripping, remove the water bath and continue to stir at 45-50°C for 2 hours.

[0032] (3) Neutralization: the alcoholysis solution is cooled to 8°C, the temperature of the ice-water bath is not more than 10°C, and 854g of 20% ammonia water is added dropwise until the pH value of the reaction solution reaches 8; the ammonium chloride generated is filtered and dried to obtain chlorine Ammonium chloride 470g.

[0033] (4) Liquid separation: the filtrate separates the lower organic phase, and...

Embodiment 3

[0036]1. Chlorination: Add 86Kg of vinyl acetate, 1Kg of 2,6-di-tert-butyl-4-methylphenol and 1Kg of benzyltriethylammonium chloride into a 200-liter jacketed enamel kettle; The temperature is 19-25°C, and 71Kg of chlorine gas is passed through for 7 hours.

[0037] 2. Alcoholysis: Slowly transfer the chlorinated solution into a 500-liter jacketed enamel kettle containing 128Kg methanol, and carry out methanolysis at 45-50°C with temperature control. After 2 hours, turn the kettle off, turn off the cooling water, and continue stirring at 48°C 2 hours.

[0038] 3. Neutralization: Put cooling brine into the jacket to cool down to 7°C, control the temperature not to exceed 10°C, and add 68.5Kg of 25% ammonia water dropwise. Neutralize until pH 8 is reached. The neutralizing solution was dried with a centrifuge to obtain 48.5Kg of ammonium chloride.

[0039] 4. Washing: The centrifuged mother liquor is separated into layers, and the lower organic phase is separated. The organic...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a green process for preparing chloroacetaldehyde dimethyl acetal from vinyl acetate, which comprises the following steps: directly chlorinating vinyl acetate in the presence ofa polymerization inhibitor and a polarity induction reagent to obtain (1,2-dichloroethyl) acetate, adding (1,2-dichloroethyl) acetate into methanol, carrying out methanolysis, neutralizing with ammonia water, and carrying out post-treatment to obtain chloroacetaldehyde dimethyl acetal. A free radical polymerization inhibitor needs to be added before chlorination of vinyl acetate to prevent free radical polymerization in the chlorination process, and quaternary ammonium salt or quaternary phosphonium salt is used as a polarity induction reagent to promote electrophilic addition reaction of chlorine to vinyl acetate. According to the method, expensive raw materials and reagents are not used, operation is easy and convenient, the yield is high, the byproduct ammonium chloride is convenient to recycle, benefits are good, and industrialization is easy to achieve.

Description

technical field [0001] The invention relates to the technical field of organic chemistry and pharmaceutical intermediates, in particular to a green method for preparing chloroacetaldehyde dialkyl acetal from vinyl acetate. Background technique [0002] Chloroacetaldehyde dimethyl acetal (system name: 2-chloro-1,1-dimethoxyethane), can be used as an intermediate of various fine chemicals such as spices, medicines, and pesticides, and is also an important organic synthesis reagent . At present, there are many published preparation methods of chloroacetaldehyde dimethyl acetal, mainly including direct method and indirect method. Aldehyde aqueous solution, and then undergo rectification to obtain a chloroacetaldehyde aqueous solution with a concentration of more than 40%, and then the chloroacetaldehyde aqueous solution with a concentration of more than 40% and excess methanol are catalyzed by an appropriate amount of acid, through azeotropic dehydration [US20160272610] or anhy...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C07C43/313C07C41/50C07C41/58C07C69/63C07C67/287C07C67/29C07C43/13C07C41/26C07C47/14C07C45/00C07C45/63
CPCC07C41/50C07C41/58C07C67/287C07C67/29C07C41/26C07C45/00C07C45/63
Inventor 张文勤
Owner 石家庄欧特佳化工有限公司