High selectivity synthesis method of p-nitrobenzaldehyde

A p-nitrobenzaldehyde, high-selectivity technology, applied in the field of preparation of known compounds, can solve the problems of expensive catalysts, difficult to recycle and recycle, etc., to reduce the generation of organic by-products, shorten the reaction time, and reduce bromine The effect of consumption

Inactive Publication Date: 2013-11-06
HEFEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Liu Changchun applied this method to the synthesis of p-nitrobenzaldehyde, using RuHAP as a catalyst, oxygen oxidation of p-nitrobenzyl alcohol under normal pressure to prepare p-nitrobenzaldehyde, this method can significantly improve the selection of p-nitrobenzaldehyde synthesis and improve product yield, but the catalyst is expensive and difficult to recycle and recycle

Method used

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  • High selectivity synthesis method of p-nitrobenzaldehyde
  • High selectivity synthesis method of p-nitrobenzaldehyde
  • High selectivity synthesis method of p-nitrobenzaldehyde

Examples

Experimental program
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Effect test

Embodiment 1

[0027] In a 250mL three-necked flask, add 100g of dichloroethane, 20.5g of p-nitrotoluene, 1.0g of di(2-ethyl)hexyl peroxydicarbonate dissolved in 16g of dichloroethane, at 45°C, Slowly add 12.3 g of bromine dropwise in 30-60 minutes. After the dropwise addition, maintain the temperature and stir for 3 hours to form a light yellow solution. After adding 0.5 g of di(2-ethyl)hexyl peroxydicarbonate dissolved in 8.0 g of dichloroethane, slowly add 9.5 g of 27% hydrogen peroxide dropwise in 30 minutes, and control the temperature at 65-68° C. to stir the solution for 4 hours. Add 65g of 30% sodium carbonate aqueous solution to the bromination solution, stir and raise the temperature to recover 80g of dichloroethane, and stir the mixed solution at 80-95°C for 16h. Stand to separate the aqueous phase and the organic phase containing p-nitrobenzyl alcohol. Transfer the organic phase into a stainless steel pressure vessel, 0.23g triphenylphosphine bismuth salt, at a temperature of 50...

Embodiment 2

[0029] In a 250mL three-necked flask, add 80g of dichloroethane, and then add 20.5g of p-nitrotoluene, 1.2g of di(2-ethyl)hexyl peroxydicarbonate dissolved in 19g of dichloroethane, at 45 At ℃, slowly add 12.7g of bromine dropwise within 30min. After the dropwise addition, stir and react at 50°C for 3.5h, then slowly add 9.5g of 27% hydrogen peroxide dropwise within 30min, and control the temperature at 60-62°C to stir the solution for 5h. Add 65g of 30% sodium carbonate aqueous solution to this bromination solution, stir and raise the temperature to recover 70g of dichloroethane, and stir the mixed solution at 80-95°C for 16h. Stand to separate the aqueous phase and the organic phase containing p-nitrobenzyl alcohol. Transfer the organic phase into a stainless steel pressure vessel, 0.23g triphenylphosphine bismuth salt, at a temperature of 50-70°C, 8.1×10 5The reaction was stirred for 28 h under Pa oxygen atmosphere pressure. After the reaction, add 20 g of water under nor...

Embodiment 3

[0031] In a 250mL three-necked flask, add 80g of dichloroethane, followed by adding 20.5g of p-nitrotoluene, 1.2g of di(2-ethyl)hexyl peroxydicarbonate dissolved in 19g of dichloroethane, at 45°C Slowly add 12.7g of bromine dropwise within 30min. After the dropwise addition, stir and react for 3.5h, slowly add 9.5g of 27% hydrogen peroxide dropwise within 30min, control the temperature at 65-68°C and stir the solution for 5h. Add 65g of 30% sodium carbonate aqueous solution to this bromination solution, stir and raise the temperature to recover 80g of dichloroethane, and stir the mixed solution at 80-95°C for 16h. The aqueous phase and the organic phase containing p-nitrobenzyl alcohol and the like were separated by standing. Transfer the organic phase into a stainless steel pressure vessel, 0.23g triphenylphosphine palladium salt, at a temperature of 50-70°C, 8.1×10 5 The reaction was stirred under Pa oxygen atmosphere pressure for 22 h. After the reaction, add 20 g of wate...

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Abstract

A high selectivity synthesis method of p-nitrobenzaldehyde comprises the following steps: firstly, adding p-nitrotoluene, peroxycarbonate used as catalyst and dichloroethane used as solvent in a reactor, dropping bromine at 40-50 DEG C under stirring, then reacting at 50-60 DEG C to ensure that the color of bromine fades, adding hydrogen peroxide to react at 60-70 DEG C for no less than 4 hours and prepare 4-nitrobenzyl bormide; and secondly, adding 25-35% sodium carbonate solution to hydrolyze at 80-95 DEG C and generate p-nitrobenzyl alcohol, standing to separate, and finally using oxygen as oxidant to react for no less than 25 hours in the presence of catalyst triphenylphosphine metal salt organic complex under the conditions that the temperature is 50-90 DEG C and the pressure 5.1*10<5>-1.0*10<6>. The overall yield of the method is no less than 70%, the product purity is no less than 99% and the dosage of bromine is 50-60% of the theoretical amount.

Description

1. Technical field [0001] The present invention relates to a kind of preparation method of known compound, specifically a kind of highly selective synthetic method of p-nitrobenzaldehyde. 2. Background technology [0002] p-Nitrobenzaldehyde is a white or light yellow crystalline powder with a melting point of 105-107°C, slightly soluble in water and ether, soluble in benzene, ethanol and glacial acetic acid, capable of sublimation and volatilization with water vapor. Molecular formula is C 7 h 5 NO 3 , relative molecular mass 151.12. Its structural formula is: [0003] [0004] p-Nitrobenzaldehyde is an important intermediate for organic synthesis and preparation of fine chemicals such as medicines, dyes, and pesticides. Many important functional chemical products. In the field of important intermediates used in the synthesis of pesticides, medicines, dyes, photosensitive materials and liquid crystal materials, such as the preparation of p-nitrobenzene-2-butenone, ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C205/44C07C201/12B01J31/02B01J31/22
Inventor 彭新华石文文陈天云戴志宏
Owner HEFEI UNIV OF TECH
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