Method for preparing 3,5-dichloroaniline

A technology of dichloroaniline and dichlorobromobenzene, which is applied in the field of preparation of chlorine product 3,5-dichloroaniline, can solve the problems of difficult source of raw materials, harsh reaction conditions, low yield, etc. Simple, high-yield results

Inactive Publication Date: 2013-05-15
JIANGSU ANPON ELECTROCHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Some of these methods have difficult sources of raw materials, some harsh reaction conditions, and low yields.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Add 81 grams (0.5 mol) of 2,4-dichloroaniline, 200 grams of water, and 130 grams of 31% hydrochloric acid into a 1000 ml four-neck flask with a stirrer and a thermometer, and stir and add 80.4 grams of bromine (0.5 mol), and continued to stir for 40 minutes after dropping to obtain a reaction solution of 2-bromo-4,6-dichloroaniline hydrochloride, added 150 g (2.5 mol) of isopropanol, cooled to -10°C, and added dropwise (10 %) containing 35 grams of sodium nitrite (0.507 mol), after stirring for 50 minutes after dripping, the temperature was slowly raised to boiling at 5~15°C / 10 minutes, the azeotrope was collected, and the layers were separated to obtain 3,5- 110 grams of dichlorobromobenzene; add 110 grams of 3,5-dichlorobromobenzene, 150 grams of 28 (w / w)% ammonia water, and 5 grams (0.035 moles) of catalyst cuprous oxide into the autoclave, heat up, and control the temperature at 170 °C for 5 hours to complete the reaction. 77.8 g of 3,5-dichloroaniline was distille...

Embodiment 2

[0022] Add 81 grams (0.5 moles) of 2,4-dichloroaniline, 300 grams of water and 50 grams of 98% sulfuric acid into a 1000 ml four-necked flask with a stirrer and a thermometer, stir and add 80.4 grams (0.5 moles) of bromine dropwise, After dropping, continue stirring for 40 minutes to obtain a reaction liquid of 2-bromo-4,6-dichloroaniline hydrochloride, add 100 g (2.17 moles) of ethanol, cool to -10°C, add dropwise (15%) nitrous acid Aqueous solution of 35 grams of sodium (0.507 mol), after dripping and stirring for 50 minutes, slowly heat up to boiling at 5~15°C / 10 minutes, collect the azeotrope, stand for layer separation, and obtain 3,5-dichlorobromobenzene 108 grams; add 108 grams of 3,5-dichlorobromobenzene, 150 grams of 28 (w / w)% ammonia water, and 4.5 grams (0.031 moles) of catalyst cuprous oxide into the autoclave, raise the temperature, and react at 170°C for 5 hours. End the reaction. 75.2 g of 3,5-dichloroaniline was distilled, with a yield of 92%.

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Abstract

The invention discloses a method for preparing 3,5-dichloroaniline. The method comprises the following steps of: (1) dissolving 2,4-dichloroaniline in hydrochloric acid or sulfuric acid to form 2,4-dichloroaniline hydrochloride or sulfate, dropwise adding bromine at room temperature while stirring, thereby obtaining the hydrochloride or sulfate of 2-bromo-4,6-dichloroaniline; (2) adding ethanol or isopropanol to the hydrochloride or sulfate reaction liquid of 2-bromo-4,6-dichloroaniline obtained in the step (1), cooling to about 0 DEG C, dropwise adding the aqueous solution of sodium nitrite, continuing stirring for 30-50 minutes after dropping, slowly increasing the temperature until boiling, and evaporating out 3,5-dichlorobromobenzene for future use; and (3) adding ammonia water and a catalyst to the 3,5-dichlorobromobenzene obtained in the step (2) for reacting for 3-6 hours at the temperature of 130-180 DEG C, thereby obtaining 3,5-dichloroaniline. The method provided by the invention has the advantages that raw materials are easily available, reaction is simple, conditions are mild, yield is high.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a preparation method of chlorine product 3,5-dichloroaniline. Background technique [0002] 3,5-Dichloroaniline is a medicine, pesticide, and dye intermediate, its English name is 3,5-Dichloroaniline, CAS626-43-7, the pure product is needle crystal, m.p.51~53℃, b.p.259~260℃ / 98.7kPa, soluble in ethanol, ether, diethyl carbonate, insoluble in water, highly toxic and corrosive. In "Synthesis of 3,5-Dichloroaniline and Its Application in Pesticides" on pages 6-9 of Volume 21, No. 2, Jiangsu Chemical Industry, 1993, Cao Guanghong reviewed the synthesis method of 3,5-dichloroaniline. There are 2,4-dichloro-4-nitroaniline method, acetanilide method, o-nitroaniline method, mixed dichlorobenzene method, polyhalogenated aniline dehalogenation hydrogenolysis method, 1,3,5-trichloroaniline ammonia solution method , 3,5-dichlorobenzamide Hoffman method. Some of these methods h...

Claims

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Application Information

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IPC IPC(8): C07C211/52C07C209/10
Inventor 陈灿银
Owner JIANGSU ANPON ELECTROCHEM
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