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 problems of high waste liquid treatment costs, unavoidable by-products of o-nitrobenzoic acid, and too strong oxidation conditions, etc. problems, to achieve the effect of convenient environmental protection treatment, short preparation process time, mild and moderate oxidation

Active Publication Date: 2021-07-09
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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  • 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, wherein the preparation method comprises the following steps: (1) adding o-nitrobenzyl alcohol, a catalyst, a bromide salt and a solvent into a reaction kettle, and uniformly stirring at room temperature; (2) controlling the reaction temperature, slowly dropwise adding a sodium hypochlorite solution into the reaction kettle, and simultaneously adding a weakly alkaline substance or an acidic substance to control the pH value of the reaction; (3) standing for layering, adding an organic solvent to extract a product, and concentrating to obtain a crude product; and (4) crystallizing by using an organic solvent, centrifuging, and drying in vacuum to obtain o-nitrobenzaldehyde. According to the method, 2-(2,2,6,6-tetramethylpiperidine nitroxide radical-4-subunit) acetic acid which is low in price and easy to obtain is used as a catalyst, the sodium hypochlorite solution is used as an oxidizing agent, a mixed solvent of water and chlorinated hydrocarbon is used as a reaction solvent, the o-nitrobenzaldehyde is prepared through oxidation under the mild temperature condition, the raw materials are low in price 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 Applications(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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