Preparation method of o-nitrobenzaldehyde

A technology of o-nitrobenzaldehyde and o-nitrotoluene, applied in the field of preparation of leading nitrobenzaldehyde, can solve the problems of low selectivity, high production cost, environmental pollution, etc., achieve great application prospects, simple method, Environmentally friendly effect

Inactive Publication Date: 2019-10-15
石家庄海象科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the synthetic routes reported in the literature still have problems such as low selectivity, low yield, high production cost, and environmental pollution.

Method used

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  • Preparation method of o-nitrobenzaldehyde
  • Preparation method of o-nitrobenzaldehyde

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] The synthesis of embodiment 1 o-nitrobenzaldehyde

[0014] Before starting the reaction, take a 250ml three-neck flask, add o-nitrotoluene (24ml, 0.2mol), 30ml 1,2-dichloroethane, and 60ml deionized water to it in turn, and stir for 5 minutes with a magnet. Weigh 2 g of azobisisobutyronitrile and add it into the mixed solution of o-nitrotoluene, raise the temperature of the solution to 65° C., and stir for 15 min. Take 6ml of liquid bromine and add it to the dropping funnel, and add about 10ml of deionized water above the liquid bromine to prevent the liquid bromine from volatilizing. Add liquid bromine dropwise to the solution, and the dropwise addition time of liquid bromine is 1.5h. After the liquid bromine was added dropwise, the color of the solution was reddish brown, and the reddish brown in the solution faded to light yellow after continuing to react for about 2 hours. Add 1.5 g of azobisisobutyronitrile to the solution and stir for 15 min, measure 20 ml of 30...

Embodiment 2

[0015] The synthesis of embodiment 2 o-nitrobenzaldehyde

[0016] According to the above-mentioned method for preparing o-nitrobenzyl alcohol, 21 g of crude o-nitrobenzyl alcohol before recrystallization was obtained, which was oxidized according to the ratio of the amount of o-nitrobenzyl alcohol to nitric acid being 1:2.5. Add 23ml of concentrated nitric acid to 22ml of distilled water to prepare dilute nitric acid with a concentration of 40%. Add o-nitrobenzyl alcohol to the dilute nitric acid solution and stir, heat up to 60°C, react for 4 hours, and cool down the solution to 40°C , in the solution, slowly drip the sodium hydroxide solution that concentration is 25%, adjust the pH=8~9 of solution, drop to room temperature and wait for o-nitrobenzaldehyde to separate out, filter and remove filtrate, filter cake is washed to neutrality with distilled water 19 g of light yellow o-nitrobenzaldehyde was obtained, and 25 ml of tetrachloroethylene was added to heat up to 90° C. f...

Embodiment 3

[0017] The synthesis of embodiment 3 o-nitrobenzaldehyde

[0018] According to the method described in embodiment 1, obtain the o-nitrobenzaldehyde of 16g ​​light yellow, then carry out the acidification treatment of gac, get the medical grade gac (powder) of 10g, add 50ml dilute sulfuric acid solution (1.5mol / L), in N 2 In the case of protection, heat to 50°C, react for 2 hours, then filter the activated carbon, and wash away excess dilute sulfuric acid with distilled water. Dissolve the light yellow o-nitrobenzaldehyde in 10ml of methanol, add 0.8g of acid-treated activated carbon, heat up to 60°C, stir for 40min, filter to obtain a transparent o-nitrobenzaldehyde solution, and spin evaporate at 30°C. White o-nitrobenzaldehyde (15 g, 50%) was obtained with a purity of 99.9%.

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Abstract

The invention relates to a preparation method of o-nitrobenzaldehyde, and is mainly applied to the field of medicine synthesis. According to the method disclosed by the invention, o-nitrotoluene is taken as a raw material, an initiator is added and subjected to a bromination reaction with liquid bromine in an oil-water two-phase solvent, hydrolyzed by sodium carbonate, and oxidized by dilute nitric acid to obtain crude o-nitrobenzaldehyde, and finally purification and discoloration are performed to obtain white o-nitrobenzaldehyde with the purity is 99.9%.

Description

technical field [0001] The invention relates to a preparation method of o-nitrobenzaldehyde. O-nitrobenzaldehyde is an important intermediate of medicine and organic synthesis, belonging to the field of organic synthesis. Background technique [0002] O-nitrobenzaldehyde is an important intermediate in medicine and organic synthesis, and is widely used in the fields of medicine, pesticides and dyes. In medicine, nitrobenzaldehyde is mainly used in the synthesis of drugs for the treatment of cardiovascular diseases, such as: nifedipine, nisoldipine, encaramide, etc. It is also the parent of ambroxol hydrochloride (3,5-di Bromoanthranilic aldehyde) key compound. [0003] In recent years, due to the decline in air quality in some cities, respiratory infections are likely to be induced, and the demand for ambroxol hydrochloride injections and related pharmaceuticals has continued to expand, further increasing the market demand for o-nitrobenzaldehyde, especially for the synthes...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C201/12C07C205/44
CPCC07C201/12C07C205/44C07C205/11C07C205/19
Inventor 王文博李峥张博颖
Owner 石家庄海象科技有限公司
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