Method for continuously synthesizing ethyl 4-chloroacetoacetates

A technology of chloroacetoacetic acid and esters, which is applied in the preparation of acyl halides, carboxylic acid halides, organic chemistry, etc., can solve the problems of small effective cooling area, difficult subsequent separation, low utilization rate of equipment, etc., and achieve a solution to the reaction temperature Low temperature, controlled reaction temperature, and easy rectification

Active Publication Date: 2016-06-22
山东德澳精细化学品有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are still many dichlorinated impurities in the first product synthesized by this method, which brings difficulties for the subsequent separation of the product; at the same time, the scraper in the scraper falling film reactor needs to be in a rotating state to make the reaction solution film. Therefore, the actual effective cooling area of ​​the reactor is small, and the utilization rate of the equipment is low

Method used

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  • Method for continuously synthesizing ethyl 4-chloroacetoacetates
  • Method for continuously synthesizing ethyl 4-chloroacetoacetates
  • Method for continuously synthesizing ethyl 4-chloroacetoacetates

Examples

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Effect test

Embodiment 1

[0029] Diketene is mixed with dichloromethane to prepare a solution containing about 7.68-7.70% of diketene, cooled to -5~0℃, and the configured diketene solution enters through a Teflon distributor (30mm above the distributor) -In the falling film reactor cooled by the refrigerant at 5~0℃, the flow rate is 50ml / min, the chlorine gas enters the reactor through the gas distribution pipe (polytetrafluoroethylene, opening number 40, pore diameter 0.4mm), flow rate 75L / h; diene The molar ratio of ketone to chlorine is 1.00:0.97 (±0.02); the gas phase such as unreacted chlorine enters the tail gas absorber; after the reaction liquid flows out of the reactor, it enters the esterification reactor through a gas-liquid separator.

[0030] The chlorination reaction liquid enters the esterification reactor and is mixed with ethanol for esterification reaction. The temperature of the esterification reaction is controlled at 5~10℃; the amount of ethanol added is controlled at diketene: ethanol...

Embodiment 2

[0032] Diketene is mixed with dichloromethane to prepare a solution containing about 5% of diketene, cooled to -15~-10℃, and the configured diketene solution enters through the distributor (nickel, the upper liquid layer of the distributor 40mm) In the falling film reactor cooled by the refrigerant at -15~-10℃, the flow rate is 77ml / min, and the chlorine gas enters the reactor through the gas distribution pipe (nickel tube, opening 60, aperture 0.1mm), and the flow rate is 79L / h. The molar ratio of diketene to chlorine is 1.00:1.02. Unreacted chlorine and other gaseous phases enter the tail gas absorber; after the reaction liquid flows out of the reactor, it enters the esterification reactor through a gas-liquid separator.

[0033] The chlorination reaction liquid enters the esterification reactor and is mixed with methanol for esterification reaction. The esterification reaction temperature is controlled at -10~0℃; the amount of methanol added is controlled at diketene: methanol...

Embodiment 3

[0035] Diketene is mixed with chloroform to prepare a solution containing about 30% of diketene, cooled to 10~15℃, and the configured diketene solution enters through the distributor (Hastelloy, the upper liquid layer of the distributor 20mm) In a falling film reactor cooled by a refrigerant at 10 to 15°C, the flow rate is 12ml / min, and the chlorine gas enters the reactor through a gas-phase distribution pipe (Hastelloy, 20 openings, 1mm diameter), and a flow rate of 65L / h. The molar ratio of diketene to chlorine is 1.00:0.85. Unreacted chlorine and other gaseous phases enter the tail gas absorber; after the reaction liquid flows out of the reactor, it enters the esterification reactor through a gas-liquid separator.

[0036] The chlorination reaction liquid enters the esterification reactor and is mixed with isopropanol for esterification reaction. The temperature of the esterification reaction is controlled at 10-15°C; the amount of isopropanol added is controlled at diketene: ...

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Abstract

The invention relates to a method for continuously synthesizing ethyl 4-chloroacetoacetates. The method comprises the following steps: pumping a cooled diketene solution into a falling film reactor through a metering pump, and enabling the cooled diketene solution to uniformly form a film through a distributor, and flow into the reactor from a tower top; meanwhile, controlling the flow of chlorine gas through a gas flow meter; introducing the chlorine gas into the reactor through a gas distributor; carrying out a reaction on the diketene and the chlorine gas on the surface of the falling film reactor; after the reaction is finished, enabling reaction liquid to flow out from a tower bottom and enter an esterification reaction kettle; pumping in different alcohols and overflowing into a next esterification reaction kettle to continually react; absorbing hydrogen chloride gas, which is generated in a reaction process, with water; after the reaction is finished, washing with water and neutralizing to remove the residual hydrogen chloride; distilling an organic phase to recycle a solvent and excessive alcohol raw materials to obtain a crude product; rectifying the crude product to obtain an ethyl 4-chloroacetoacetates product. With the adoption of the method, reaction time can be shortened, energy consumption is reduced, polychlorides are controlled, reaction selectivity is improved, rectification is relatively easy, and yield and purity of the product are improved.

Description

[Technical Field] [0001] The invention belongs to the technical field of organic molecule synthesis, and specifically is a method for continuously synthesizing 4-chloroacetoacetate. [Background technique] [0002] Ethyl 4-chloroacetoacetate is an important intermediate for the production of cardio-cerebrovascular drugs amlodipine, atorvastatin calcium, beta-lactam antibiotics cefixime, ceftazidime and other drugs. [0003] [0004] Reaction equation of ethyl 4-chloroacetoacetate [0005] The current production method (publication number cn102746151, cn101007793) is mainly: diketene solution is -15~-30℃, chlorine gas is introduced, low temperature stirring, after the reaction is completed, alcohol is added for esterification reaction, after the reaction is completed, the refined The yield of the product obtained by distillation is 80-88%. This process is a low-temperature batch reaction, and it is difficult to uniformly control the temperature. The contact time between chlorine and ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/14C07C69/72C07C51/58C07C53/46
CPCC07C51/58C07C67/14C07C53/46C07C69/72
Inventor 王朝阳毛海舫舒卫进徐少华丰树雷李帅恩穆金君姚跃良孙揭阳
Owner 山东德澳精细化学品有限公司
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