A preparing method of 2-nitrobenzaldehyde

A technology of o-nitrobenzaldehyde and azobisalkyl nitrile, applied in the field of preparation of known compounds, can solve problems such as production cost and industrial operation not having obvious advantages, difficult to regenerate metal oxides, poor thermal stability and the like , to reduce the generation of organic by-products, reduce the cost of industrial preparation, and avoid pollution.

Inactive Publication Date: 2016-03-30
NANJING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method requires the application of chlorine, and benzyl chloride has a lacrimal effect; the second-step nitration reaction uses a mixture of nitric acid and niobium pentoxide solid superacid as a nitrating agent, and the selectivity of ortho-position nitration is poor, but still forms o-nitrobenzyl chloride, meta The three isomers of nitrobenzyl chloride and p-nitrobenzyl chloride are difficult to separate, and they also have a strong lachrymatory effect, and metal oxides are difficult to recycle.
[0008] (3) Using o-nitrotoluene as a raw material, react with bromine to form o-nitrobenzyl bromide, then catalyze hydrolysis with sodium carbonate to form o-

Method used

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  • A preparing method of 2-nitrobenzaldehyde
  • A preparing method of 2-nitrobenzaldehyde
  • A preparing method of 2-nitrobenzaldehyde

Examples

Experimental program
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Embodiment 1

[0029] In the reactor, add 100g of chlorobenzene, 16.4g of o-nitrotoluene, 3.3g of azobisisovaleronitrile, slowly add 11.5g of bromine dropwise within 30min at 50°C, after the dropwise addition, stir and heat to reflux React until the bromine color fades. Slowly add 8.5 g of 27.5% hydrogen peroxide dropwise within 30 min, and stir and reflux for 2 h. Add 54.7g of 30% potassium carbonate aqueous solution to the reaction solution, stir and reflux for 16 hours, recover chlorobenzene by distillation, cool and stand to separate the aqueous phase and the organic phase containing o-nitrobenzyl alcohol. Transfer the organic phase into the reactor, add 3.2g of sodium hydroxide, stir and control the temperature at 30°C, add 58.5g of 35% hydrogen peroxide dropwise within 30min, and heat to reflux for 23h. After the reaction was completed, it was cooled to room temperature, and the organic phase was separated by standing. After washing, the organic solvent was concentrated, and 13.6 g of...

Embodiment 2

[0031] In the reactor, add 100g of chlorobenzene, 16.4g of o-nitrotoluene, and 1.5g of azobisisoheptanonitrile, and slowly add 10.8g of bromine dropwise within 30 minutes at 45°C. After the dropwise addition, stir and heat to reflux to react until the bromine color fades. Slowly add 8.5 g of 27.5% hydrogen peroxide dropwise within 30 min, and stir and reflux for 2 h. Add 60.0 g of 30% potassium carbonate aqueous solution to the reaction solution, stir and reflux for 16 hours, recover chlorobenzene by distillation, and cool and stand to separate the aqueous phase and the organic phase containing o-nitrobenzyl alcohol. Transfer the organic phase into the reactor, add 1.5g of sodium hydroxide, stir and control the temperature at 30°C, add 75.0g of 27.5% hydrogen peroxide dropwise within 30min, and heat to reflux for 23h. After the reaction was completed, cool to room temperature, stand to separate the organic phase, concentrate the organic solvent after washing, and refine with ...

Embodiment 3

[0033]In the reactor, add 100g of o-dichlorobenzene, 16.4g of o-nitrotoluene, 1.5g of azobisisooctanonitrile, and slowly add 10.8g of bromine dropwise within 30min at 45°C. After the dropwise addition, stir and heat The reaction was refluxed until the color of bromine faded. Slowly add 8.5 g of 27.5% hydrogen peroxide dropwise within 30 min, and stir and reflux for 2 h. Add 60.0 g of 30% potassium carbonate aqueous solution to the reaction solution, stir and reflux for 16 hours, recover ortho-dichlorobenzene by distillation, and cool and stand to separate the water phase and the organic phase containing o-nitrobenzyl alcohol. Transfer the organic phase into the reactor, add 1.5g of sodium hydroxide, stir and control the temperature at 30°C, add 41.3g of 50% hydrogen peroxide dropwise within 30min, and heat to reflux for 23h. After the reaction was completed, it was cooled to room temperature, and the organic phase was separated by standing. After washing, the organic solvent ...

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Abstract

The invention discloses a preparing method of 2-nitrobenzaldehyde. 2-nitrotoluene is adopted as a raw material and is brominated with bromine under catalytic function of azo-bis alkyl nitrile to generate 2-nitrobenzyl bromide and hydrogen bromide. The 2-nitrobenzyl bromide is hydrolyzed under catalytic function of an aqueous carbonate solution to generate 2-nitrobenzyl alcohol. The 2-nitrobenzyl alcohol is oxidized with hydrogen peroxide under catalytic function of sodium hydroxide to generate the objective compound, namely the 2-nitrobenzaldehyde. A hydrogen peroxide oxidation manner is adopted by the method, thus improving cleanliness of industrial preparation reactions, and reducing environment pollution. Oxidation is catalyzed by adopting the inorganic solid alkali catalyst and no metal organic complex catalyst is used, thus improving reaction stability and greatly reducing the cost of industrial preparation. An azo-bis alkyl nitrile solid catalyst in place of a peroxydicarbonate liquid catalyst is adopted to catalyze the bromination, thus improving reaction operation safety of industrial preparation. The method increases the product yield. The yield of the method is increased by about 5% than that of traditional industrial methods at present. The total yield can reach 77% and product purity is higher than 99%.

Description

technical field [0001] The present invention relates to a kind of preparation method of known compound, specifically a kind of industrial clean preparation method of o-nitrobenzaldehyde. Background technique [0002] O-Nitrobenzaldehyde is a yellowish solid with a melting point of 41-43°C, insoluble in water, and easily soluble in organic solvents such as alcohols, ethers, aromatic hydrocarbons, halogenated hydrocarbons, and esters. The molecular formula of o-nitrobenzaldehyde is C 7 h 5 NO 3 , the relative molecular mass is 151.1. The chemical structural formula of o-nitrobenzaldehyde is: [0003] [0004] O-nitrobenzaldehyde is a class of important pharmaceutical intermediate organic functional materials, mainly used for the preparation of nifedipine and other drugs for the prevention and treatment of hypertension and cardiovascular diseases, as well as for the preparation of expectorant and anti-inflammatory drugs such as ambroxine. O-nitrobenzaldehyde is also an ...

Claims

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Application Information

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IPC IPC(8): C07C201/12C07C205/44
Inventor 彭新华马庆国徐俊辉
Owner NANJING UNIV OF SCI & TECH
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