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Preparation methods and application of nitrobenzaldehyde and 2-chloro-4-fluoro-5-nitrobenzaldehyde

A technology of nitrobenzaldehyde and nitration reaction is applied in the field of preparation of organic compounds, and can solve the problems of many operation steps, long cycle, potential safety hazards and the like

Active Publication Date: 2021-01-15
NANTONG JIANGSHAN AGROCHEM & CHEM LIMITED LIABILITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, these methods have common disadvantages: high cost and serious environmental pollution.
Yet this preparation method has the following disadvantages: (1) the benzaldehyde with substituent is directly nitrated, and due to the oxidation of nitric acid, the aldehyde group is inevitably partially oxidized to carboxylic acid; (2) the benzaldehyde with substituent, During the preparation process, it will float out with water vapor and adhere to the condenser and other positions, causing system blockage and bringing greater safety hazards to production; (3) the preparation of benzaldehyde with substituents requires cooling crystallization and solid-liquid separation. Many steps, long cycle, etc.

Method used

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  • Preparation methods and application of nitrobenzaldehyde and 2-chloro-4-fluoro-5-nitrobenzaldehyde
  • Preparation methods and application of nitrobenzaldehyde and 2-chloro-4-fluoro-5-nitrobenzaldehyde
  • Preparation methods and application of nitrobenzaldehyde and 2-chloro-4-fluoro-5-nitrobenzaldehyde

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preparation example Construction

[0026] In order to solve the problems of the technologies described above, a first aspect of the present invention provides a kind of preparation method of nitrobenzaldehyde, comprising the following steps:

[0027] (1) Nitration reaction: Add benzyl dichloride with substituents to the mixed solution of sulfuric acid and nitric acid, control the reaction temperature not higher than 60°C, and react for 1-10h;

[0028] (2) Hydrolysis reaction: raise the temperature of the reaction system to 60-120° C., react for 1-20 hours, and stop the reaction.

[0029] In a preferred embodiment, the preparation method of said nitrobenzaldehyde comprises the following steps:

[0030] (1) Nitration reaction: Add benzyl dichloride with substituents to the mixed solution of sulfuric acid and nitric acid, control the reaction temperature not higher than 60°C, and react until the residual amount of benzyl dichloride with substituents is less than 0.5% ;

[0031] (2) Hydrolysis reaction: The tempe...

Embodiment 1

[0081] Embodiment 1 provides a kind of preparation method of 2-chloro-4-fluoro-5-nitrobenzaldehyde, comprising the following steps:

[0082] (1) Preparation of mixed acid: add 102g of 98% sulfuric acid in a 1000ml beaker, take an ice bath outside the beaker, slowly add 51g of 65% nitric acid, and the internal temperature is not higher than 60°C;

[0083] (2) Nitration reaction: 153 g of the prepared mixed acid was put into a four-necked flask with a stirring paddle, a dropping funnel, and a thermometer. The external bath of the four-necked flask was a low-temperature circulation tank heat conduction oil bath, and the temperature of the oil bath was set at 60°C; Start stirring, and drop 107.8 g of 2-chloro-4-fluoro-benzyl dichloride into the four-necked flask through the dropping funnel; control the inner temperature of the four-necked flask to 60°C for nitration reaction; after the addition is completed, monitor by liquid chromatography In the case of the reaction, when the re...

Embodiment 2

[0087] Embodiment 2 provides a kind of preparation method of 2-chloro-4-fluoro-5-nitrobenzaldehyde, comprising the following steps:

[0088] (1) Preparation of mixed acid: add 204g of 98% sulfuric acid in a 1000ml beaker, put it in an ice bath outside the beaker, slowly add 51g of 65% nitric acid, and the internal temperature is not higher than 60°C;

[0089] (2) Nitrification reaction: drop into the prepared mixed acid 255g (204g of 98% sulfuric acid, 51g of 65% nitric acid) in the four-necked flask with stirring paddle, dropping funnel, thermometer, and the external bath of the four-necked flask is a low-temperature circulation tank for heat conduction Oil bath, set the temperature of the oil bath to 40°C; start stirring, drop 107.8g of 2-chloro-4-fluoro-benzyl dichloride into the four-necked flask through the dropping funnel; control the internal temperature of the four-necked flask to 40°C for nitration Reaction; after the dropwise addition, the progress of the reaction is...

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Abstract

The invention relates to the technical field of preparation methods of organic compounds, in particular to preparation methods and application of nitrobenzaldehyde and 2-chloro-4-fluoro-5-nitrobenzaldehyde. The preparation method of nitrobenzaldehyde comprises the following steps of: (1) nitration reaction: adding benzyl dichloride with substituent groups into a mixed solution of sulfuric acid andnitric acid, controlling the reaction temperature to be not higher than 60 DEG C, and reacting until the benzyl dichloride with substituent groups is completely reacted; and (2) hydrolysis reaction:heating a reaction system to 60-120 DEG C, and stopping the reaction until a nitration product of the benzyl dichloride with substituent groups is completely reacted. The structure of the benzyl dichloride with substituent groups is shown as a formula I. The positions of the substituent groups R are at least one of ortho-position, meta-position and para-position. The number of the substituent groups R is 1-5, and the substituent groups R are selected from at least one of hydrogen, alkyl and halogen; The method is simple in reaction operation, high in atom utilization rate, good in yield, highin product purity, low in cost and easy to realize industrialization.

Description

technical field [0001] The invention relates to the technical field of preparation methods of organic compounds, in particular to a preparation method and application of nitrobenzaldehyde and 2-chloro-4-fluoro-5-nitrobenzaldehyde. Background technique [0002] As an important fine organic chemical intermediate, nitrobenzaldehyde has a wide range of industrial applications and a large demand, and is widely used in pharmaceutical fuels and organic synthesis. At present, the research on the synthesis route of o-nitrobenzaldehyde and p-nitrobenzaldehyde is relatively extensive at home and abroad. In terms of chemical synthesis methods, there are mainly: oxidative nitration method, displacement method, and reduction method. However, these methods all have common disadvantages: high cost and serious environmental pollution. At present, the electrochemical method is used to oxidize nitrotoluene to prepare nitrobenzaldehyde. This method is too inefficient and still remains in the l...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C205/44C07C201/12
CPCC07C201/12C07C201/08C07C205/44C07C205/12
Inventor 董垒张小宏贲震东吴金泉郭磊蒋阳阳杜鹏里张子炜杜辉
Owner NANTONG JIANGSHAN AGROCHEM & CHEM LIMITED LIABILITY