Method for preparing aminostyrene through catalytic hydrogenation of nitrostyrene

A technology of nitrostyrene and aminostyrene, which is applied in the field of preparation of aminostyrene by catalytic hydrogenation of nitrostyrene, which can solve the problems of reducing product quality, producing sulfur-containing by-products, high temperature, etc., and achieve the effect of reducing the amount of use

Active Publication Date: 2015-10-14
CHANGCHUN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of this catalyst is that during the hydrogenation reaction, sulfur-containing by-products are produced, which reduces product quality and limits the reuse of solvents
[0004] At present, there are the following main problems in the preparation of aminostyrene by hydrogenation: (1) The reaction is mostly carried out in toxic, harmful and volatile organic solvents such as toluene and tetrahydrofuran
(2) The CoS mentioned above 3 、Co 3 o 4 , Fe 2 o 3 As well as catalysts such as Au and Ag, the activity is low, and the reaction requires a higher temperature (110-160°C) and a longer time
(3) The method disclosed in WO2009071727, which uses the strong interaction between the metal and the support produced by high-temperature reduction to m

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Example 1 3-nitrostyrene hydrogenation

[0016] Add 5mL H to a 50mL autoclave 2 O, 0.25g 3-nitrostyrene, 0.15g reduced catalyst Pt / SnO 2 -Sb2 o 3 , the mass content of Pt is 0.5%, the molar ratio of Sb to Sn is 0.1:1, the equal volume impregnation method is used to load Pt, and the catalyst is heated in H before the reaction. 2 Reduction at 250°C for 2h. Tighten the reactor, use high-purity N at room temperature 2 Purge for 5 minutes to remove the air in the reactor. The reactor was preheated in a constant temperature water bath at 50°C for 15 minutes, and filled with 4MPa H 2 , start stirring, and react for 3h. The reactor was cooled down, and the reaction product was extracted with toluene and analyzed by gas chromatography. The conversion rate of nitrostyrene is 96.7%, and the selectivity of aminostyrene is 98.1%.

Embodiment 2

[0017] Example 2 Hydrogenation of 3-nitrostyrene

[0018] The mass content of Pt is 1.0%, the reaction time is 2h, and other conditions are the same as in Example 1. The conversion rate of nitrostyrene is 98.2%, and the selectivity of aminostyrene is 98.4%.

Embodiment 3

[0020] The reaction time is 4h, and the catalyst and other conditions are the same as in Example 2. The conversion rate of nitrostyrene is 100%, and the selectivity of aminostyrene is 97.3%.

[0021] From Example 2 and Example 3, it can be seen that the selectivity of aminostyrene is almost unchanged when the reaction time is prolonged, indicating that Pt / SnO 2 -Sb 2 o 3 There is almost no catalytic activity for the hydrogenation of the target product aminostyrene.

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PUM

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Abstract

The invention relates to a method for preparing aminostyrene through catalytic hydrogenation of nitrostyrene. According to the method, in environment-friendly solvents H2O, ethanol, n-heptane, H2O-ethanol or H2O-n-heptane, nitrostyrene is catalyzed by Pt/SnO2-Sb2O3 serving as a catalyst to have hydrogenation reaction at 35-120 DEG C to prepare aminostyrene. Pt/SnO2-Sb2O3 has high selectivity in generation of aminostyrene; in H2O, ethanol and n-heptane, the selectivity for aminostyrene is respectively greater than 97%, greater than 95% and greater than 96%; the reaction rate in H2O is highest and the yield of aminostyrene is greater than 97%; no accumulation of harmful intermediates such as phenyl hydroxylamine is generated in the reaction process; since Pt/SnO2-Sb2O3 almost has no catalytic activity for hydrogenation of aminostyrene, the yield of aminostyrene does not decrease when time goes by after the reactants are completely converted.

Description

technical field [0001] The invention relates to a method for preparing aminostyrene by catalytic hydrogenation of nitrostyrene. Specifically related to Pt / SnO 2 -Sb 2 o 3 As a catalyst, in the green solvent H 2 O, ethanol, n-heptane, H 2 O-ethanol or H 2 In the O-n-heptane system, the method for preparing aminostyrene by catalyzing the selective hydrogenation of nitrostyrene. Background technique [0002] Aminostyrene is a kind of aromatic amine compounds, and it is an intermediate for the production of important chemical products such as medicines, stabilizers, fungicides, insecticides, and herbicides. [0003] Catalytic hydrogenation of nitrostyrene is an effective method for preparing aminostyrene. In nitrostyrene molecules, both nitro and vinyl groups are easily reduced by hydrogenation. The development of a catalyst with high activity for hydrogenation of nitrogroups and low activity for hydrogenation of vinyl groups is an important way to improve the efficiency ...

Claims

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Application Information

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IPC IPC(8): C07C211/45C07C209/36B01J23/644
Inventor 孟祥春种芬芬
Owner CHANGCHUN UNIV OF TECH
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