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Method for preparing m-phenylenediamine

A technology of m-phenylenediamine and m-dinitrobenzene, which is applied in chemical instruments and methods, preparation of amino compounds, preparation of organic compounds, etc., can solve unreported, nickel flammable, conversion rate of m-dinitrobenzene Low-level problems, to achieve the effect of simple production process, mild operating conditions and good selectivity

Inactive Publication Date: 2008-12-17
中国中化股份有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, nickel is flammable, has poor safety in use, and is used in a large amount; the skeleton nickel is very brittle and easily broken and deactivated; the specific gravity of nickel is large, and high-speed stirring is required to ensure the complete reaction.
Teng Junjiang of Qingdao University of Science and Technology and others used 5%, 10% palladium carbon or 3% platinum carbon as single active component catalysts to catalyze the hydrogenation of m-phenylenediamine [Journal of Qin g dao University of Science and Technolo g y Vol.24( 9), 2003], m-dinitrobenzene conversion rate is lower than 60%
The method of producing m-phenylenediamine by the hydrogenation of m-dinitrobenzene catalyzed by palladium-ruthenium binary composite catalyst has not been reported so far

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0011] Example 1: Catalyst Preparation

[0012] Dissolve 1 g of palladium chloride in 2 ml of concentrated hydrochloric acid, and then dilute with 20 ml of water; dissolve 0.78 g of ruthenium chloride in 10 ml of water, and mix the two solutions together for later use. Add 120 milliliters of water and 9 grams of activated carbon treated with nitric acid into a 250 milliliter four-neck flask (with a stirrer, thermometer, condenser and dropping funnel), and add the pre-prepared chlorine dropwise under stirring at 70-85 ° C. The mixed solution of palladium chloride and ruthenium chloride was continued to stir for 10 minutes after dropping. Another 2 ml of 85% hydrazine hydrate was added and incubated for 30 minutes. Afterwards, the temperature was lowered to 25° C., filtered, and washed several times with deionized water. The obtained catalyst (Pd 6%, Ru 4%) was stored in a sealed bottle for future use.

[0013] In the same way, the catalyst with the required content can be ob...

example 2

[0015] Dissolve 1 g of palladium chloride in 2 ml of concentrated hydrochloric acid, and then dilute with 20 ml of water; dissolve 0.78 g of ruthenium chloride in 10 ml of water, and mix the two solutions together for later use. Mix 120ml of water and 9g of Al 2 o 3 Add it to a 250ml four-necked bottle (with a stirrer, thermometer, condenser and dropping funnel), add the pre-prepared mixed solution of palladium chloride and ruthenium chloride dropwise under stirring at 70-85°C, and continue stirring after dropping 180 minutes. Another 2 ml of 85% hydrazine hydrate was added and incubated for 30 minutes. Then cool down to 25°C, filter, and wash with deionized water several times. The obtained catalyst (Pd 6%, Ru 4%) was stored in a sealed bottle for future use.

[0016] In the same way, the catalyst with the required content can be obtained by adjusting the addition of palladium and ruthenium (for example, Pd 1-10%, Ru 1-8%).

example 3

[0018] Add 20 grams of m-dinitrobenzene, 0.042 grams of Pd-Ru / C catalyst (Pd 5%, Ru 3%), and 100 milliliters of methanol into the autoclave with stirring, and replace the gas and air in the autoclave with nitrogen and hydrogen respectively for 3 times , and then increase the hydrogen pressure in the kettle to 1.5Mpa, start stirring, heat up, and control the reaction temperature to 100°C to carry out the hydrogenation reaction. After the hydrogenation reaction is complete, m-phenylenediamine methanol solution is obtained, and the catalyst is separated by filtration for recycling. Methanol was distilled off under normal pressure, and then distilled under reduced pressure to obtain 12.65 g of m-phenylenediamine, with a yield of 98.5%, and a purity of 99% through gas chromatography analysis (area normalization method, the same below).

[0019] The above-mentioned catalyst was recycled 5 times, and the purity and yield of the obtained product were basically the same.

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PUM

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Abstract

The invention discloses a method for preparing metaphenylene diamine by catalytic hydrogenation of m-dinitrobenzene, comprising the following steps of: taking m-dinitrobenzene as a raw material, and carrying out hydrogenation reduction in the solvent of alcohol or benzene under the existence of a palladium-ruthenium loaded catalyst. The reaction conditions are temperature of 20 DEG C to150 DEG C, pressure of 0.1MPa to 6.0MPa and input amount of catalyst of 0.1g to 1.0g / 100g nitryl materials. The method for preparing the metaphenylene diamine provided by the invention has advantages of simple production technology, moderate operation conditions and easy control. The catalyst used for the reaction has high activity, good selectivity, low cost and long service life.

Description

technical field [0001] The invention belongs to the field of chemical product manufacturing, and in particular relates to a method for preparing m-phenylenediamine. Background technique [0002] m-Phenylenediamine is an important intermediate of dyes, pesticides, medicines, and functional materials, and is currently widely used as a raw material for the production of resorcinol. In the past, the method of producing m-phenylenediamine basically used iron powder reduction or alkali sulfide reduction process. In addition to producing a large amount of three wastes, this process also has the disadvantages of poor product quality and low yield. The process of producing m-phenylenediamine by catalytic hydrogenation with a skeleton nickel catalyst developed in recent years has solved the problem of large amount of three wastes, see CN1439456A, CN1462740A. However, nickel is flammable, has poor safety in use, and is used in a large amount; the skeleton nickel is very brittle and ea...

Claims

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Application Information

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IPC IPC(8): C07C211/51C07C209/36
Inventor 李付刚李文骁
Owner 中国中化股份有限公司
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