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A kind of preparation method of o-nitrobenzaldehyde

A technology of o-nitrobenzaldehyde and o-nitrobenzyl alcohol, which is applied in the field of o-nitrobenzaldehyde preparation, can solve the problem of high waste liquid treatment costs, too strong oxidation conditions, and unavoidable by-products of o-nitrobenzoic acid, etc. problems, to achieve the effect of convenient environmental protection treatment, short preparation process time and high selectivity

Active Publication Date: 2022-01-25
陕西西岳制药(扶风)有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] Therefore, in the existing method of oxidizing o-nitrobenzyl alcohol to prepare o-nitrobenzaldehyde, either the oxidation condition is too strong, the generation of o-nitrobenzoic acid by-product is unavoidable, or the oxidizing reagent used needs multi-step synthesis, so The waste liquid treatment cost is relatively high, which limits the large-scale and safe production of o-nitrobenzaldehyde

Method used

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  • A kind of preparation method of o-nitrobenzaldehyde

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Effect test

Embodiment 1

[0029] In the 2000ml reaction flask, add 153g of o-nitrobenzyl alcohol, 1.5g of 2-(2,2,6,6-tetramethylpiperidinyl nitroxide radical-4-ylidene) acetic acid, 300g of dichloromethane 1.5g of potassium bromide was dissolved in 300g of water and added to the reaction system, cooled to 5°C with an ice bath, and 84g of NaHCO 3 Dissolve it in 1000g of 10% sodium hypochlorite solution, adjust its pH to about 8.5, slowly add it to the reaction bottle, control the dropping speed so that the reaction temperature is not higher than 10°C, after the dropping is completed, TLC detects that the reaction is complete in 2 hours, and the reaction The liquid was allowed to stand for liquid separation, the aqueous phase was extracted with 500gx2 dichloromethane, the organic phase was combined, washed once with 500g of water, and the organic phase was washed with anhydrous Na 2 SO 4 Dry, filter, concentrate the light yellow oil, add 300g of methyl tert-butyl ether, stir evenly, stand at 0°C for cry...

Embodiment 2

[0031] Add 7.65 g of o-nitrobenzyl alcohol, 7.5 mg of 2-(2,2,6,6-tetramethylpiperidinyl nitroxide radical-4-ylidene) acetic acid, 15 g of dichlorobenzyl alcohol in a 100 ml reaction flask Methane and 7.5mg of sodium bromide were dissolved in 15g of water and added to the reaction system, cooled to 5°C with an ice bath, and 4.2g of NaHCO 3 Dissolve in 65g of 10% sodium hypochlorite solution, adjust its pH to about 8.5, slowly add it to the reaction bottle, control the dropping speed so that the reaction temperature is not higher than 20°C, after the dropping is completed, TLC detects that the reaction is complete in 0.5 hours, and the reaction The liquid was allowed to stand for liquid separation, the aqueous phase was extracted with 25gx2 dichloromethane, the organic phase was combined, washed once with 25g of water, and the organic phase was washed with anhydrous Na 2 SO 4 Dry, filter, and concentrate the obtained light yellow oil, add 15g of petroleum ether, stir evenly, st...

Embodiment 3

[0033] Add 7.65 g of o-nitrobenzyl alcohol, 0.8 mg of 2-(2,2,6,6-tetramethylpiperidinyl nitroxide radical-4-ylidene) acetic acid, 15 g of dichlorobenzyl alcohol into a 100 ml reaction flask Methane and 7.5mg of potassium bromide were dissolved in 15g of water and added to the reaction system, cooled to 5°C with an ice bath, and 4.2g of NaHCO 3 Dissolve in 65g of 10% sodium hypochlorite solution, adjust its pH to about 8.5, slowly add it to the reaction bottle, control the dropping speed so that the reaction temperature is not higher than 20°C, after the dropping is completed, TLC detects that the reaction is complete in 0.5 hours, and the reaction The liquid was allowed to stand for liquid separation, the aqueous phase was extracted with 25gx2 dichloromethane, the organic phase was combined, washed once with 25g of water, and the organic phase was washed with anhydrous Na 2 SO 4 Dry, filter, concentrate the light yellow oil, add 15g of petroleum ether, stir evenly, stand at 0...

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Abstract

The invention discloses a preparation method of o-nitrobenzaldehyde, which comprises the following steps: (1), adding o-nitrobenzyl alcohol, a catalyst, a bromide salt and a solvent into a reaction kettle, stirring evenly at room temperature; (2), Control the reaction temperature, slowly add sodium hypochlorite solution dropwise to the reactor, and add weakly alkaline substances or acidic substances to control the pH value of the reaction; (3), static layering, add an organic solvent to extract the product, and concentrate to obtain a crude product; (4) 1. Using an organic solvent to crystallize, centrifuging, and vacuum drying to obtain o-nitrobenzaldehyde. The present invention uses cheap and easy-to-get 2-(2,2,6,6-tetramethylpiperidinyl nitroxide radical-4-ylidene) acetic acid as a catalyst, uses sodium hypochlorite solution as an oxidant, and mixes water and chlorinated hydrocarbons The solvent is used as a reaction solvent, and o-nitrobenzaldehyde is obtained by oxidation under mild temperature conditions. The raw materials in the invention are cheap and easy to obtain, the reaction time is short, the reaction selectivity is high, and the yield is high.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a preparation method of o-nitrobenzaldehyde. Background technique [0002] O-Nitrobenzaldehyde is an important pharmaceutical and organic synthesis intermediate, widely used in the preparation of medicines, dyes and pesticides, etc. It is an important intermediate for the synthesis of expectorant ambroxol hydrochloride parent 3,5-dibromoanthranilic aldehyde. [0003] At present, there are many starting materials for the synthesis of o-nitrobenzaldehyde, mainly o-nitrotoluene, o-nitrobenzyl alcohol, benzaldehyde, o-nitrobenzyl diacetate, o-nitrobenzoic acid, etc. Wherein the synthesis method using o-nitrobenzyl alcohol as a raw material has the shortest synthesis route and the highest efficiency. [0004] In the patent document CN 108164421A; about 60% nitric acid is used as an oxidant to oxidize o-nitrobenzyl alcohol under the condition of 65-70° C. The e...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C201/12C07C201/16C07C205/44
CPCC07C201/12C07C201/16C07C205/44
Inventor 王灿辉黄治炎杨爽赵晨华郝光胜李敬强胡西儒
Owner 陕西西岳制药(扶风)有限公司
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