Preparation method of 3-chloro-4-fluoroaniline hydrochloride

A technology of fluoroaniline hydrochloride and fluoroaniline, which is applied in the field of preparation of pharmaceutical intermediates, can solve the problems of low total yield, troublesome post-processing, environmental pollution of industrial wastewater, etc., and achieves stable product properties, less by-products, and avoidance of Effects of Environmental Pollution

Inactive Publication Date: 2014-04-09
JIANGSU JIXIAN GREEN CHEM TECH RESINST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Among them, both method (2) and method (3) need to be chlorinated by chlorine gas, which is highly toxic and difficult to control the reaction conditions, and in method (3), expensive fluorobenzene is used as the raw material, the route cost is high, and the economic benefit is low
At present, the reduction of nitro groups in industrial production is still dominated by iron powder reduction. The post-treatment is troublesome, the total yield is low, and the consumption of raw materials is high. The resulting industrial wastewater is serious to environmental pollution.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Add 100kg of 3,4-dichloronitrobenzene, 36.3kg of potassium fluoride and 500L of DMSO into the reactor, start stirring, heat in an oil bath, and reflux for 5 hours. Follow the reaction by TLC until the raw materials completely disappear. Filter to remove inorganic salts, and steam distill the filtered filtrate to obtain 78.4 kg of light yellow crystal 3-chloro-4-fluoronitrobenzene with a yield of 86%.

Embodiment 2

[0025] Add 100kg of 3,4-dichloronitrobenzene, 79.1kg of cesium fluoride and 500LDMF into the reaction kettle, start stirring, heat in an oil bath, and reflux for 5 hours. Follow the reaction by TLC until the raw materials completely disappear. Filter to remove inorganic salts, and steam distill the filtered filtrate to obtain 82.1 kg of light yellow crystal 3-chloro-4-fluoronitrobenzene with a yield of 90%.

Embodiment 3

[0027] Add 40kg 3-chloro-4-fluoronitrobenzene, 2kg 10%Pd-C and 400L methanol to the reaction kettle, replace the air with hydrogen twice, pass hydrogen, stir at room temperature, react for 6 hours, and follow the reaction by TLC to Raw material disappears completely. Evacuate the residual hydrogen, filter, filter the reaction solution to remove the catalyst, recover the solvent, distill under reduced pressure, collect the fraction at 116 ° C ~ 120 ° C / 21.33 kPa, cool and crystallize to obtain 29.8 kg of white crystals, the yield is 90%, the purity of HPLC 99.5%.

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PUM

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Abstract

The invention provides a preparation method of 3-chloro-4-fluoroaniline hydrochloride. The 3-chloro-4-fluoroaniline hydrochloride is prepared from a raw material 3,4-dichloronitrobenzene through a three-step reaction comprising the steps of fluorine displacement, hydrogenation reduction and salt formation. The preparation method has the advantages of few byproducts, stable product properties, low reaction apparatus requirements because of the implementation of the nitro group reduction reaction using hydrogen and Pd-C at normal temperature, recycling of a solvent and Pd-C, and avoiding of the environmental pollution by introducing an excess HCl gas into an alkaline solution.

Description

technical field [0001] The invention relates to a preparation method of a pharmaceutical intermediate, in particular to a preparation method of 3-chloro-4-fluoroaniline hydrochloride. Background technique [0002] 3-Chloro-4-fluoroaniline is a very important starting material in the process of synthesizing the anticancer drug gefitinib, and is also an important intermediate in the synthesis of the antibacterial drug norfloxacin. In addition, 3-chloro-4-fluoroaniline is also an important intermediate in the synthesis of fluorine-containing pesticides, herbicides, plant growth regulators, and fungicides. The domestic production capacity of 3-chloro-4-fluoroaniline is about 1,000 tons, and the output is only a few hundred tons, and the product quality is not good enough to meet the needs of the domestic pharmaceutical industry in particular. Due to the small scale of domestic production enterprises, the product quality and output cannot meet the demand, especially the high-qua...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C211/52C07C209/00C07C209/36
Inventor 李可庆
Owner JIANGSU JIXIAN GREEN CHEM TECH RESINST
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