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Method for synthesizing 1, 8-diaminonaphthalene through selective reduction of 1, 8-dinitronaphthalene

A technology of dinitronaphthalene selectivity and diaminonaphthalene, which is applied to the preparation of amino compounds, chemical instruments and methods, and the preparation of organic compounds, can solve the problems of low yield and difficult industrial production, and achieve high selectivity and high yield. The effect of high efficiency and easy distillation

Pending Publication Date: 2020-05-08
常州悦朋科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Difficult to use in industrial production due to low yield

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] The first step: take 30g of 1,8-dinitronaphthalene, 300g of ethanol, use Pd as catalyst, and prepare Pd / C by adsorbing Pd on C, the addition of Pd / C is 1.7g, and the mass percentage of Pd is 5% Left and right, not only has a good catalytic effect, but also is cheap; add it to the high-pressure reactor, seal the reactor, replace the air in the reactor with nitrogen for about 3 times, and then replace the nitrogen with hydrogen for about 3 times;

[0024] The second step: raise the temperature in the kettle to 65°C, keep it warm for 6 hours, and control the pressure at 1.5MPa;

[0025] Step 3: After the reaction, take out the reaction solution and filter out the catalyst, distill off the solvent under reduced pressure, cool to below -10°C, crystallize and filter out 20.6 g of the product 1,8-diaminonaphthalene. After testing, the purity of the product is above 97.2%, and the yield is 94.7%.

example 2

[0027] Step 1: Add 80g of 1,8-dinitronaphthalene, 300g of isopropanol, and 4.8g of Pd / C into the autoclave, seal the autoclave, replace the air in the autoclave with nitrogen for about 3 times, and then replace it with hydrogen Nitrogen about 3 times;

[0028] The second step: raise the temperature in the kettle to 65°C, keep it warm for 4 hours, and control the pressure at 1.5MPa;

[0029] Step 3: After the reaction is over, take out the reaction liquid and filter out the catalyst, distill off the solvent under reduced pressure, cool to below -10°C, crystallize and filter out 55.8g of the product 1,8-diaminonaphthalene, and the purity of the product is 98.3% after testing Above, the yield is 96.2%.

Embodiment 3

[0031] Take 30g of 1,8-dinitronaphthalene, 300g of ethanol, and 1.8g of Pd / C into the autoclave, seal the autoclave, replace the air in the autoclave with nitrogen for about 3 times, and then replace the nitrogen with hydrogen for about 3 times;

[0032] The second step: raise the temperature in the kettle to 70°C, keep it warm for 10 hours, and control the pressure at 2MPa;

[0033] Step 3: After the reaction is over, take out the reaction liquid and filter out the catalyst, distill off the solvent under reduced pressure, cool to below -10°C, crystallize and filter out the product 1,8-diaminonaphthalene 21.2g with a purity of 99.1% and a yield of 97.7 %.

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PUM

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Abstract

The invention discloses a method for preparing 1, 8-diaminonaphthalene by selective reduction of 1, 8-dinitronaphthalene, which is a method for only generating the 1, 8-diaminonaphthalene by adding acatalyst into a solvent and controlling the temperature and time to completely reduce nitryl. The used solvent can be selected from one of methanol, ethanol, isopropanol or DMF, the used catalyst is one of nickel, cobalt, platinum and palladium noble metals, and the catalytic reduction only reduces the nitryl, so the method has the advantages of high selectivity, high reduction rate, almost 100% reduction, high yield (95% or above) and less than 5% of wastewater amount, solves the problems of incomplete reduction and low yield of previous methods, and is suitable for industrial production. Thepurity of the 1, 8-diaminonaphthalene prepared by the method is up to 99% or above, the reduction rate of the raw material is high, the reduction rate is almost 100%, the yield is 95% or above, and the produced wastewater is less than 5% of the total wastewater.

Description

technical field [0001] The invention relates to a method for selectively reducing 1,8-dinitronaphthalene to synthesize 1,8-diaminonaphthalene. Background technique [0002] 1,8-diaminonaphthalene is an important dye intermediate, gray-red to gray or dark brown needle crystal, molecular formula is C 10 h 10 N 2 , CAS No.: 479-27-6, molecular weight 158.1998, 1,8-diaminonaphthalene is an important intermediate for the manufacture of oil-soluble pigments, with an annual output of more than 10,000 tons, mainly used for the synthesis of solvent orange 60 and solvent red 135. This kind of pigment is widely used in the coloring of polystyrene, plexiglass, rigid polyvinyl chloride and ABS. [0003] CN: 1100403A discloses that dinitronaphthalene, iron powder, alcohol, water, glacial acetic acid, caustic soda, and sodium bisulfite are prepared according to a certain ratio, and after mixing, stirring, heating, heat preservation, dilution, precipitation and filtration, Drying and ot...

Claims

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Application Information

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IPC IPC(8): C07C209/36C07C211/58
CPCC07C209/36C07C211/58
Inventor 吴建中徐佩涛
Owner 常州悦朋科技有限公司
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