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Preparation method of o-carboxybenzaldehyde

A technology of o-carboxybenzaldehyde and phthalide, which is applied in the field of preparation of o-carboxybenzaldehyde, can solve the problems of environmental and human harm, unsatisfactory controllability, low yield and the like, and achieves reduction of pollutant discharge and guarantee of raw material utilization. The effect of high rate and reaction efficiency

Active Publication Date: 2021-02-12
舞阳威森生物医药有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] This invention uses bromine as a reactant, which is easy to volatilize and can freeze into a solid when the temperature is low. It is extremely toxic and corrosive, and the controllability of this experiment is not ideal.
[0009] In summary, in the prior art, the preparation process of o-carboxybenzaldehyde is not only harmful to the environment and human body, but also has a low yield

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0045] A kind of preparation method of o-carboxybenzaldehyde, it comprises the steps:

[0046] (1) put 94.35kg (330mol) of dibromohydantoin and 200L of dichloromethane in the reactor, stir and be warmed up to 60 DEG C to reflux; 0.40kg (1.8mol) of initiator 2,3-diphenylbutyronitrile is used Dichloromethane 30L was dissolved, and phthalide (80kg, 600moL) was dissolved in dichloromethane 90L, then slowly dropped into the reactor simultaneously from two feeding ports; wherein the dropping rate of the initiator 2,3-diphenylbutyronitrile was 50mL / min, the dropping rate of phthalide is 150mL / min;

[0047] (2) after the reaction is complete, add 100L of water for washing, the water layer is reclaimed in barrels, and the methylene chloride layer is transferred into the second reactor, and the mass ratio of phthalide and water described in this step is 1:2;

[0048] The second part of the reactor is heated with warm water in the jacket, keeping the temperature of the water tank at 30-...

Embodiment 2

[0055] A kind of preparation method of o-carboxybenzaldehyde, it comprises the steps:

[0056] (1) drop into NBS 117.48kg (660moL) in reactor, methylene dichloride 200L, stir and be warming up to 60 ℃ of refluxes; The initiator benzoyl peroxide (0.32kg, 1.3mol) is dissolved with methylene dichloride 30L, After phthalide (80kg, 600mol) dissolves with methylene dichloride 90L, slowly drips in the reactor simultaneously from two feeding ports; Wherein the rate of addition of initiator benzoyl peroxide is 50mL / min, and the rate of addition of phthalide is 150mL / min;

[0057] (2) after the reaction is complete, add 100L of water for washing, the water layer is reclaimed in barrels, and the methylene chloride layer is transferred into the second reactor, and the mass ratio of phthalide and water described in this step is 1:2;

[0058] The second part of the reactor is heated with warm water in the jacket, keeping the temperature of the water tank at 30-32°C, and the vacuum degree a...

Embodiment 3

[0065] A kind of preparation method of o-carboxybenzaldehyde, it comprises the steps:

[0066] (1) drop into pyridine hydrobromide perbromide (70.36kg, 220moL), methylene dichloride 200L in reactor, stir and be warming up to 60 ℃ of backflows; By initiator azobisisobutyronitrile (0.35kg, 2.1 mol) is dissolved with methylene dichloride 30L, after phthalide (80kg, 600mol) is dissolved with methylene dichloride 90L, slowly drips in the reactor simultaneously from two feeding ports; Wherein the rate of addition of initiator azobisisobutyronitrile is 50mL / min, the dropping rate of phthalide is 150mL / min;

[0067] (2) after the reaction is complete, add 100L of water for washing, the water layer is reclaimed in barrels, and the methylene chloride layer is transferred into the second reactor, and the mass ratio of phthalide and water described in this step is 1:2;

[0068] The second part of the reactor is heated with warm water in the jacket, keeping the temperature of the water ta...

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Abstract

The invention belongs to the technical field of preparation of drug intermediates, and particularly relates to a preparation method of o-carboxybenzaldehyde. The method comprises the following steps:a crude o-carboxybenzaldehyde product preparation step: taking phthalide as a raw material, carrying out bromination reaction under the action of a bromination reagent and an initiator to obtain 3-bromophthalide, and then carrying out hydrolysis reaction to obtain a crude o-carboxybenzaldehyde product; salifying and purifying, namely adjusting the solution of the o-carboxybenzaldehyde crude product to be weakly alkaline by using inorganic base, filtering to obtain a filter cake, dissolving the filter cake, adjusting the pH value to be acidic, cooling, crystallizing and filtering to obtain o-carboxybenzaldehyde; wherein the bromination reagent is tetrabromo cyclic ketone, dibromohydantoin, NBS, pyridine hydrobromide over-bromide, over-bromo quaternary ammonium salt or quaternary phosphoniumsalt. The preparation method of o-carboxybenzaldehyde provided by the invention is low in pollution, mild in condition, high in safety, high in product purity and yield, and suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of preparation of pharmaceutical intermediates, and in particular relates to a preparation method of o-carboxybenzaldehyde. Background technique [0002] O-carboxybenzaldehyde is an important intermediate for synthesizing antipyretic analgesics. At present, the preparation technology of o-carboxybenzaldehyde includes the following: [0003] 1. Take phthalide as a raw material, bromine water as a reaction reagent, in organic solvent chloroform, heat to reflux, feed nitrogen protection in the reaction process, remove the solvent under reduced pressure after the reaction, cooling, crystallization, suction filtration to obtain 3-bromo Phthalide; then add 3-bromophthalide into the hydrolysis kettle, carry out water bath heating, cooling, crystallization, suction filtration to obtain the o-carboxybenzaldehyde wet product; finally recrystallize the o-carboxybenzaldehyde wet product to obtain the o-carboxybenzaldehy...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/09C07C51/41C07C51/02C07C51/43C07C65/30C07D307/88
CPCC07C51/09C07C51/412C07C51/02C07C51/43C07D307/88C07C65/30Y02P20/55
Inventor 彭学东张梅赵金召
Owner 舞阳威森生物医药有限公司
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