CN106631727A - Method for preparing 2,5-difluorobenzaldehyde through continuous oxidation of 2,5-difluorotoluene - Google Patents

Method for preparing 2,5-difluorobenzaldehyde through continuous oxidation of 2,5-difluorotoluene Download PDF

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Publication number
CN106631727A
CN106631727A CN201610972044.XA CN201610972044A CN106631727A CN 106631727 A CN106631727 A CN 106631727A CN 201610972044 A CN201610972044 A CN 201610972044A CN 106631727 A CN106631727 A CN 106631727A
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reaction
difluoro
difluoro toluenes
toluenes
difluorobenzaldehydes
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Inventor
刘建武
蒋鑫
张跃
严生虎
沈介发
马晓明
陈代祥
辜顺林
倪风超
李彦飞
王秋红
陈明珠
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Changzhou University
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Changzhou University
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    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/27Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation
    • C07C45/28Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation of CHx-moieties
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/0093Microreactors, e.g. miniaturised or microfabricated reactors
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/24Stationary reactors without moving elements inside
    • B01J19/2415Tubular reactors
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00049Controlling or regulating processes
    • B01J2219/00164Controlling or regulating processes controlling the flow
    • B01J2219/00166Controlling or regulating processes controlling the flow controlling the residence time inside the reactor vessel
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00781Aspects relating to microreactors
    • B01J2219/0095Control aspects
    • B01J2219/00984Residence time

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  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
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Abstract

The invention provides a method for preparing 2,5-difluorobenzaldehyde through continuous oxidation of 2,5-difluorotoluene and belongs to the technical field of organic synthesis processes. According to the method, a 2,5-difluorobenzaldehyde compound is used as raw material, one or more of metal ion complexes of cobalt, molybdenum and bromine are used as catalysts, hydrogen peroxide serves as an oxidizing agent, acetic acid is used as a solvent, and 2,5-difluorotoluene oxidation is continuously performed in a tubular reactor to prepare the 2,5-difluorobenzaldehyde. The method is mild in condition, short in reaction time, high in raw material utilization rate, capable of achieving effective control to the reaction process and continuous operation, safe, stable and high in production efficiency.

Description

A kind of method that 2,5- difluoro toluenes continuous oxidation prepares 2,5- difluorobenzaldehydes
Technical field
The invention belongs to organic synthesis technology field, is related to one kind under liquid-phase reaction condition by 2,5- difluoro toluenes The method that continuous oxidation prepares 2,5- difluorobenzaldehydes, is more specifically that, for substrate, hydrogen peroxide is oxidation with 2,5- difluoro toluenes Agent, one or more metal ion complexs of cobalt, molybdenum, bromine are catalyst, and monocarboxylic acid is solvent, with different micro-structurals Tubular reactor in continuous prepare 2,5- difluorobenzaldehyde products.
Background technology
2,5- difluorobenzaldehydes, are very important fine chemicals, and it is the intermediate for synthesizing many important chemicals. Its molecular weight is 142.10, light yellow clear liquid, 67-69 DEG C of boiling point, more than 58 DEG C of flash-point.Be primarily used to medicine, agricultural chemicals, Liquid crystal material intermediate.
The synthetic process that current 2,5- difluorobenzaldehydes are reported mainly passes through 2,5- difluoro toluene side chain chlorine When changing preparation 2,5-, bis- fluorobenzyl chlorides, then 2,5- difluorobenzaldehydes are prepared by hydrolysis, concrete reaction equation is as follows:
The method in process of production, needs the depth of strict control chlorination, in case producing substantial amounts of accessory substance;And need Want substantial amounts of initiator and catalyst to shorten the time of reaction;And in the production of second step, it is necessary to strict control reaction Temperature and time, in addition it is also necessary to add substantial amounts of acidic catalyst to carry out catalytic reaction, causes substantial amounts of industrial wastewater, increase to produce into This, therefore, it is difficult to industrially really implementing.And carry out 2,5- difluoro toluenes using the continuous flow tubular reactor of ad hoc structure Continuous oxidation synthesis 2,5- difluorobenzaldehydes, can many-sided many deficiencies for solving existing process technology.
Tubular reactor is the general designation of the mini-reactor with micro-structural, compared with conventional reactor, tubular reactor With small volume, specific surface area is big, easily amplifies, and process is continuous, and quick good mixing effect, heat-transfer effect is good, high temperature high voltage resistant etc. Feature, can be had using the continuous flow tubular reactor of ad hoc structure to the mixing of reaction mass and mass transfer, diabatic process Effect control.By the control of the length to tubular reactor and reaction time, the distribution of raw material and product can be further made More optimize controllable;By adjusting the flow velocity of raw material pump substrate 2,5- difluoro toluenes are capable of achieving with oxidant in proportion into tubular type Reactor carries out reaction and greatly reduces back-mixing, further reduces the generation of side reaction, and the stability of oxidant and target are produced The selectivity of thing is also greatly improved;By arranging pressure safety valve in tubular reactor, can give off in time in reactor Excessive oxidant, it is ensured that the safety of reaction is carried out, and level of significance is minimized.The present invention adopts the pipe reaction of ad hoc structure Device carries out 2,5- difluoro toluene continuous oxidations and prepares the method for 2,5- difluorobenzaldehydes relative to conventional batch production method tool There is unrivaled advantage, and quantity-produced improvement can be industrialized for it and one important approach is provided.
The content of the invention
The present invention is directed to not enough with present on, there is provided one kind is in tubular reactor by the continuous oxygen of 2,5- difluoro toluenes The method that change prepares 2,5- difluorobenzaldehydes.This method reaction time is short, and production efficiency is high, and mass transfer, heat transfer are optimized significantly, Course of reaction is more stablized controllable.Further object of the present invention is, by the process of the present invention, to realize 2,5- bis- Stablizing for toluene fluoride continuous oxidation is controllable, reduces the generation of accessory substance.Carried by the reinforcing and process optimization of mass-and heat-transfer process The effective rate of utilization of high reaction mass, further reduces the usage amount of oxidant and catalyst and avoids during the course of the reaction The use of co-catalyst, so as to effectively save production cost further improves existing industrialized preparing process.
For achieving the above object, the technical solution used in the present invention is:
2,5- difluoro toluenes continuous oxidation is prepared 2,5- difluorobenzaldehydes by a kind of tubular reactor of employing special construction Method, carry out as steps described below:
(1) first at room temperature, by substrate 2,5- difluoro toluenes and part carboxylic acid solvent are with volume ratio 1:1 stirring mixing is equal It is even, by oxidant and part carboxylic acid solvent with volume ratio 1:1 is well mixed, and then pours metal complex mixing into 2,5- difluoros Toluene-carboxylic acid solution, sodium salt is poured into hydrogen peroxide-carboxylic acid solution;By the required reaction time, two kinds of materials are calculated It is different in flow rate, continuously squeeze into tubular reactor Jing measuring pump reacted into reaction zone after preheated mixing respectively, instead Temperature is answered to be controlled by outer loop heat-exchange system;
(2) mol ratio of reaction mass is controlled by adjusting the method for flow velocity and weight calculation, by changing tubular reactor 0.5~15mm of internal diameter of the pipeline, 25~750ml of volume carry out the 60~1500s of the time of staying of control material hybrid reaction;Reacting Cheng Hou, product exits into collecting tank from reactor end, and product rectification is separated, and unreacted 2,5- difluoro toluenes circulation is anti- Should, product 2,5- difluorobenzaldehyde rectifying is collected after purification, wherein target product 2, and the yield of 5- difluorobenzaldehydes is up to 20% ~35%.
Wherein described catalyst is cobalt, molybdenum, bromine one or more metal complex catalysts, and it mainly includes:Acetic acid Cobalt, cobalt oxalate, cobalt carbonate, cobalt naphthenate, sodium molybdate, ammonium molybdate, sodium bromide, ammonium bromide etc., wherein being with oil-soluble catalyst It is main, can fully dissolve in 2,5- difluoro toluenes, its consumption and substrate 2, the mol ratio of 5- difluoro toluenes is in (0.001~0.40) : 1, wherein preferred molar ratio is (0.01~0.25): 1.
Wherein described oxidant is hydrogen peroxide, and its solution concentration is calculated as 5%~65% with mass concentration, and preferred concentration is 5%~45%.Hydrogen peroxide is (1.0~12.0) with the preferred molar ratio of substrate 2,5- difluoro toluenes: 1.
Wherein described hydrogen peroxide, in tubular reactor, when hydrogen peroxide passes through reactor volume 50ml, hydrogen peroxide Start it is rapid decompose, discharge a large amount of molecular oxygens, when it passes through 100ml, almost molecular oxygen form now should be anti-in 100ml Answer and additionally supplement at volume isocyatic hydrogen peroxide to enter, reaction is participated in again.
Wherein described carboxylic acid solvent includes:Formic acid, acetic acid, propionic acid, butyric acid, caproic acid, octanoic acid etc..Wherein solvent and 2,5- The volume ratio of difluoro toluene is in (1~12): 1.
Wherein described reaction temperature is 60~155 DEG C, and preferable reaction temperature is 70~135 DEG C, and reaction time is 60s~1500s.
In further technical scheme, the oxidant for having neither part nor lot in reaction is first quenched with difluoromethane sodium after completion of the reaction, Then extracted by organic solvent, separated obtains after purification target product.
In above-mentioned technical proposal, described reaction system includes the difference in functionalitys such as raw material storage tank, reaction zone, collection of products area Region.Channel of reactor structure includes:Pipe once-through type channel design, cake formula pulse diameter varied narrow rectangular tube road structure, tiltedly Square cake formula pulse diameter varied narrow rectangular tube road structure, enhancing mixed type cake formula narrow rectangular tube road structure and Corning's Heart Cell channel designs.
The present invention has advantages below:
1st, the present invention adopts a kind of mode of production of serialization, and the reaction time is short, and reaction condition is gentle, and process safety can Control, production efficiency is high.
2nd, the present invention is capable of achieving the effective control to course of reaction by the tubular reactor made using different structure, makes Product rests on the step of aldehyde alcohol one.
3rd, by the way that the utilization rate of its reaction rate and raw material greatly improved to mass transfer in course of reaction, heat transfer intensification, And effectively reduce the usage amount of oxidant and catalyst, and the use of co-catalyst is avoided, there is production cost Effect is saved.
4th, the present invention is easy to operate, applied widely, and production is flexible, can be advised by the expanding production in parallel of reaction unit Mould.
Description of the drawings
Fig. 1 is the process chart that 2,5- difluoro toluenes continuous oxidation of the present invention prepares 2,5- difluorobenzaldehydes.
Fig. 2 is continuous flow tubular reactor installation drawing used in the present invention:1st, 2- head tanks, 3,4- raw material measuring pumps, 5- preheating zones, 6,7- reaction zones, 8- products are quenched collecting region.
Fig. 3 is tubular reactor channel design schematic diagram used in the present invention, wherein a- once-through types channel design, and b- justifies Cake formula pulse diameter varied narrow rectangular tube road, the oblique side cake formula pulse diameter varied narrow rectangular tube roads of c-, it is flat that d- strengthens mixed type cake formula Pipeline, the Heart Cell structures microchannel of e-Corning.
Specific embodiment
Cobalt acetate and sodium molybdate are dissolved in the 1# tanks equipped with 2,5- difluoro toluenes and acetic acid, 5# preheatings are pumped into by 3# In reactor, pre- thermal reactor is heated to 50 DEG C;Sodium bromide is dissolved in the 2# tanks equipped with hydrogen peroxide and acetic acid, is pumped by 4# In entering the pre- thermal reactors of 6#, pre- thermal reactor is heated to 50 DEG C, then by two strands of preheating materials, in being delivered to 7#, 8# reactor, Temperature of reactor is set in and reacts temperature required, and product, using 0 DEG C of cooling, collects products therefrom by flowing out in 8# reactors.
The present invention is described in detail with reference to embodiment, but the following examples are only the present invention preferably embodiment, Protection scope of the present invention is not limited thereto, technology model of any those familiar with the art in present disclosure In enclosing, technology according to the present invention scheme and its inventive concept in addition equivalent substitute or change should all cover the guarantor in the present invention Within the scope of shield.
Embodiment 1
(1) device:Determine the connected mode of tubular reactor with reference to Fig. 2, conduit types are:(3a+3b) once-through type passage+ Cake formula pulse diameter varied narrow rectangular tube road, internal diameter of the pipeline is with volume according to flow velocity and reaction time determination, heat transferring medium For conduction oil.
(2) respectively 1.01g cobalt acetates and 1.01g sodium molybdates be dissolved in into 200ml2,5- difluoro toluenes and 200ml acetic acid shapes Into mixed solution, now n (cobalt acetate):N (2,5- difluoro toluenes)=0.0025:1,1.01g sodium bromides are dissolved in into 20%H2O2 Form H2O2- acetic acid solution, now n (sodium bromide):N (2,5- difluoro toluenes)=0.0025:1,2,5- difluoro toluene-acetic acid is molten Liquid and and H2O2What-acetic acid solution was persistently exchanged heat respectively with the flow velocity of 5.33ml/min and 10.67ml/min by constant flow pump injection In tubular reactor, now n (H2O2):N (2,5- difluoro toluenes)=2:1, using Fig. 2 micro passage reactions, controlling reaction temperature 60 DEG C, time of staying 60s.0 DEG C of cooling of outlet material, reactant liquor is quenched with difluoromethane.Through GC analyses, 2,5- difluoro toluenes Conversion ratio is 45.3%, and 2,5- difluorobenzaldehyde yields are 23.1%.
Embodiment 2
(1) device:Determine the connected mode of tubular reactor with reference to Fig. 2, conduit types are:(3a+3c) once-through type passage+ Oblique side cake formula pulse diameter varied narrow rectangular tube road, internal diameter of the pipeline determines according to flow velocity and reaction time with volume, exchanges heat and be situated between Matter is conduction oil.
(2) respectively 6.06g cobalt acetates and 6.06g sodium molybdates be dissolved in into 200ml2,5- difluoro toluenes and 200ml acetic acid shapes Into mixed solution, now n (cobalt acetate):N (2,5- difluoro toluenes)=0.015:1,6.06g sodium bromides are dissolved in into 20%H2O2 Form H2O2- acetic acid solution, now n (sodium bromide):N (2,5- difluoro toluenes)=0.015:1,2,5- difluoro toluene-acetic acid solution With and H2O2The pipe that-acetic acid solution is persistently exchanged heat respectively with the flow velocity of 8.33ml/min and 16.67ml/min by constant flow pump injection In formula reactor, now n (H2O2):N (2,5- difluoro toluenes)=3:1, using Fig. 2 micro passage reactions, controlling reaction temperature 75 DEG C, time of staying 200s.0 DEG C of cooling of outlet material, reactant liquor is quenched with difluoromethane.Through GC analyses, 2,5- difluoro toluenes Conversion ratio is 49.0%, and 2,5- difluorobenzaldehyde yields are 28.7%.
Embodiment 3
(1) device:Determine the connected mode of tubular reactor with reference to Fig. 2, conduit types are:(3a+3d) once-through type passage+ Strengthen mixed type cake formula narrow rectangular tube road, internal diameter of the pipeline determines with volume according to flow velocity and reaction time, heat transferring medium For conduction oil.
(2) respectively 6.06g cobalt acetates and 6.06g sodium molybdates be dissolved in into 200ml2,5- difluoro toluenes and 200ml acetic acid shapes Into mixed solution, now n (cobalt acetate):N (2,5- difluoro toluenes)=0.015:1,6.06g sodium bromides are dissolved in into 20%H2O2 Form H2O2- acetic acid solution, now n (sodium bromide):N (2,5- difluoro toluenes)=0.015:1,2,5- difluoro toluene-acetic acid solution With and H2O2The pipe that-acetic acid solution is persistently exchanged heat respectively with the flow velocity of 8.33ml/min and 16.67ml/min by constant flow pump injection In formula reactor, now n (H2O2):N (2,5- difluoro toluenes)=3:1, using Fig. 2 micro passage reactions, controlling reaction temperature 95 DEG C, time of staying 300s.0 DEG C of cooling of outlet material, reactant liquor is quenched with difluoromethane.Through GC analyses, 2,5- difluoro toluenes Conversion ratio is 44.8%, and 2,5- difluorobenzaldehyde yields are 25.2%.
Embodiment 4
(1) device:Determine the connected mode of tubular reactor with reference to Fig. 2, conduit types are:(3a+3b) once-through type passage+ Cake formula pulse diameter varied narrow rectangular tube road, internal diameter of the pipeline is with volume according to flow velocity and reaction time determination, heat transferring medium For conduction oil.
(2) respectively 6.06g cobalt acetates and 6.06g sodium molybdates be dissolved in into 200ml2,5- difluoro toluenes and 200ml acetic acid shapes Into mixed solution, now n (cobalt acetate):N (2,5- difluoro toluenes)=0.015:1,6.06g sodium bromides are dissolved in into 25%H2O2 Form H2O2- acetic acid solution, now n (sodium bromide):N (2,5- difluoro toluenes)=0.015:1,2,5- difluoro toluene-acetic acid solution With and H2O2The pipe that-acetic acid solution is persistently exchanged heat respectively with the flow velocity of 5.33ml/min and 10.67ml/min by constant flow pump injection In formula reactor, now n (H2O2):N (2,5- difluoro toluenes)=2:1, using Fig. 2 micro passage reactions, controlling reaction temperature 110 DEG C, time of staying 600s.0 DEG C of cooling of outlet material, reactant liquor is quenched with difluoromethane.Through GC analyses, 2,5- difluoro first Benzene conversion ratio is 45.5%, and 2,5- difluorobenzaldehyde yields are 27.1%.
Embodiment 5
(1) device:Determine the connected mode of tubular reactor with reference to Fig. 2, conduit types are:(3a+3c) once-through type passage+ Oblique side cake formula pulse diameter varied narrow rectangular tube road, internal diameter of the pipeline determines according to flow velocity and reaction time with volume, exchanges heat and be situated between Matter is conduction oil.
(2) respectively 6.06g cobalt acetates and 6.06g sodium molybdates be dissolved in into 200ml2,5- difluoro toluenes and 200ml acetic acid shapes Into mixed solution, now n (cobalt acetate):N (2,5- difluoro toluenes)=0.015:1,6.06g sodium bromides are dissolved in into 35%H2O2 Form H2O2- acetic acid solution, now n (sodium bromide):N (2,5- difluoro toluenes)=0.015:1,2,5- difluoro toluene-acetic acid solution With and H2O2The pipe that-acetic acid solution is persistently exchanged heat respectively with the flow velocity of 8.33ml/min and 16.67ml/min by constant flow pump injection In formula reactor, now n (H2O2):N (2,5- difluoro toluenes)=3:1, using Fig. 2 micro passage reactions, controlling reaction temperature 125 DEG C, time of staying 900s.0 DEG C of cooling of outlet material, reactant liquor is quenched with difluoromethane.Through GC analyses, 2,5- difluoro first Benzene conversion ratio is 41.7%, and 2,5- difluorobenzaldehyde yields are 25.1%.
Embodiment 6
(1) device:Determine the connected mode of tubular reactor with reference to Fig. 2, conduit types are:(3a+3d) once-through type passage+ Strengthen mixed type cake formula narrow rectangular tube road, internal diameter of the pipeline determines with volume according to flow velocity and reaction time, heat transferring medium For conduction oil.
(2) respectively 6.06g cobalt acetates and 6.06g sodium molybdates be dissolved in into 200ml2,5- difluoro toluenes and 200ml acetic acid shapes Into mixed solution, now n (cobalt acetate):N (2,5- difluoro toluenes)=0.015:1,6.06g sodium bromides are dissolved in into 35%H2O2 Form H2O2- acetic acid solution, now n (sodium bromide):N (2,5- difluoro toluenes)=0.015:1,2,5- difluoro toluene-acetic acid solution With and H2O2The pipe that-acetic acid solution is persistently exchanged heat respectively with the flow velocity of 5.56ml/min and 11.11ml/min by constant flow pump injection In formula reactor, now n (H2O2):N (2,5- difluoro toluenes)=2:1, using Fig. 2 micro passage reactions, controlling reaction temperature 135 DEG C, time of staying 1200s.0 DEG C of cooling of outlet material, reactant liquor is quenched with difluoromethane.Through GC analyses, 2,5- difluoros Toluene conversion is 35.7%, and 2,5- difluorobenzaldehyde yields are 24.5%.
Embodiment 7
(1) device:Determine the connected mode of tubular reactor with reference to Fig. 2, conduit types are:(3a+3e) once-through type passage+ Corningde Heart Cell structures, internal diameter of the pipeline determines that heat transferring medium is with volume according to flow velocity and reaction time Conduction oil.
(2) respectively 6.06g cobalt acetates and 6.06g sodium molybdates be dissolved in into 200ml2,5- difluoro toluenes and 200ml acetic acid shapes Into mixed solution, now n (cobalt acetate):N (2,5- difluoro toluenes)=0.015:1,6.06g sodium bromides are dissolved in into 35%H2O2 Form H2O2- acetic acid solution, now n (sodium bromide):N (2,5- difluoro toluenes)=0.015:1,2,5- difluoro toluene-acetic acid solution With and H2O2The pipe that-acetic acid solution is persistently exchanged heat respectively with the flow velocity of 5.56ml/min and 11.11ml/min by constant flow pump injection In formula reactor, now n (H2O2):N (2,5- difluoro toluenes)=2:1, using Fig. 2 micro passage reactions, controlling reaction temperature 90 DEG C, time of staying 900s.0 DEG C of cooling of outlet material, reactant liquor is quenched with difluoromethane.Through GC analyses, 2,5- difluoro toluenes Conversion ratio is 31.8%, and 2,5- difluorobenzaldehyde yields are 20.0%.
Embodiment 8
(1) device:Determine the connected mode of tubular reactor with reference to Fig. 2, conduit types are:(3a+3d) once-through type passage+ Strengthen mixed type cake formula narrow rectangular tube road, internal diameter of the pipeline determines with volume according to flow velocity and reaction time, heat transferring medium For conduction oil.
(2) respectively 6.06g cobalt acetates and 6.06g sodium molybdates be dissolved in into 200ml2,5- difluoro toluenes and 200ml acetic acid shapes Into mixed solution, now n (cobalt acetate):N (2,5- difluoro toluenes)=0.015:1,6.06g sodium bromides are dissolved in into 35%H2O2 Form H2O2- acetic acid solution, now n (sodium bromide):N (2,5- difluoro toluenes)=0.015:1,2,5- difluoro toluene-acetic acid solution With and H2O2The pipe that-acetic acid solution is persistently exchanged heat respectively with the flow velocity of 5.56ml/min and 11.11ml/min by constant flow pump injection In formula reactor, now n (H2O2):N (2,5- difluoro toluenes)=2:1, using Fig. 2 micro passage reactions, controlling reaction temperature 135 DEG C, time of staying 1300s.0 DEG C of cooling of outlet material, reactant liquor is quenched with difluoromethane.Through GC analyses, 2,5- difluoros Toluene conversion is 34.9%, and 2,5- difluorobenzaldehyde yields are 20.1%.
Embodiment 9
(1) device:Determine the connected mode of tubular reactor with reference to Fig. 2, conduit types are:(3a+3c) once-through type passage+ Oblique side cake formula pulse diameter varied narrow rectangular tube road, internal diameter of the pipeline determines according to flow velocity and reaction time with volume, exchanges heat and be situated between Matter is conduction oil.
(2) respectively 6.06g cobalt acetates and 6.06g sodium molybdates be dissolved in into 200ml2,5- difluoro toluenes and 200ml acetic acid shapes Into mixed solution, now n (cobalt acetate):N (2,5- difluoro toluenes)=0.015:1,6.06g sodium bromides are dissolved in into 35%H2O2 Form H2O2- acetic acid solution, now n (sodium bromide):N (2,5- difluoro toluenes)=0.015:1,2,5- difluoro toluene-acetic acid solution With and H2O2The pipe that-acetic acid solution is persistently exchanged heat respectively with the flow velocity of 5.56ml/min and 11.11ml/min by constant flow pump injection In formula reactor, now n (H2O2):N (2,5- difluoro toluenes)=2:1, using Fig. 2 micro passage reactions, controlling reaction temperature 155 DEG C, time of staying 1500s.0 DEG C of cooling of outlet material, reactant liquor is quenched with difluoromethane.Through GC analyses, 2,5- difluoros Toluene conversion is 39.1%, and 2,5- difluorobenzaldehyde yields are 31.2%.

Claims (6)

1. one kind 2, the method that 5- difluoro toluenes continuous oxidation prepares 2,5- difluorobenzaldehydes, it is characterised in that as steps described below Carry out:
(1)Under room temperature, by substrate 2,5- difluoro toluenes and part carboxylic acid solvent are with volume ratio 1:1 is uniformly mixed, and will aoxidize Agent and part carboxylic acid solvent are with volume ratio 1:1 is well mixed, and then pours metal complex mixing into 2,5- difluoro toluenes-carboxylic acid Solution, sodium salt is poured into hydrogen peroxide-carboxylic acid solution;By the required reaction time, the not cocurrent flow of two kinds of materials is calculated Speed, continuously squeezes into tubular reactor Jing measuring pump reacted into reaction zone after preheated mixing respectively, reaction temperature by Outer loop heat-exchange system is controlled;
(2)The mol ratio of reaction mass is controlled by adjusting the method for flow velocity and weight calculation, by the pipeline for changing tubular reactor 0.5 ~ 15mm of internal diameter, 25 ~ 750ml of volume carrys out the time of staying of control material hybrid reaction;After completion of the reaction, product is from reaction Device end exits into collecting tank, and product rectification is separated, unreacted 2,5- difluoro toluenes circular response, product 2,5- difluorobenzenes Formaldehyde rectification is collected after purification.
2. one kind 2 according to claims 1, the method that 5- difluoro toluenes continuous oxidation prepares 2,5- difluorobenzaldehydes, It is characterized in that described catalyst is cobalt, molybdenum, sodium one or more metal complex catalysts, it mainly includes:Cobalt acetate, Cobalt oxalate, cobalt carbonate, cobalt naphthenate, sodium molybdate, ammonium molybdate, sodium bromide, ammonium bromide etc., wherein based on oil-soluble catalyst, Can fully dissolve in 2,5- difluoro toluenes, its consumption and substrate 2, the mol ratio of 5- difluoro toluenes exists(0.001~0.40): 1, Wherein preferred molar ratio is(0.01~0.25)∶1.
3. one kind 2 according to claims 1, the method that 5- difluoro toluenes continuous oxidation prepares 2,5- difluorobenzaldehydes, It is characterized in that described oxidant is hydrogen peroxide, its solution concentration is calculated as 5% ~ 65% with mass concentration, preferred concentration is 5% ~ 45%, hydrogen peroxide and substrate 2, the preferred molar ratio of 5- difluoro toluenes is(1.0~12.0)∶1.
4. one kind 2 according to claims 1, the method that 5- difluoro toluenes continuous oxidation prepares 2,5- difluorobenzaldehydes, It is characterized in that described carboxylic acid solvent includes:Formic acid, acetic acid, propionic acid, butyric acid, caproic acid, octanoic acid;Wherein solvent and 2,5- difluoros The volume ratio of toluene exists(1~12)∶1.
5. one kind 2 according to claims 1, the method that 5- difluoro toluenes continuous oxidation prepares 2,5- difluorobenzaldehydes, It is characterized in that:Reaction temperature is 60 ~ 155 DEG C, and preferable reaction temperature is 70 ~ 135 DEG C, reaction time 60s ~ 1500s.
6. one kind 2 according to claims 1, the method that 5- difluoro toluenes continuous oxidation prepares 2,5- difluorobenzaldehydes, It is characterized in that total overall reaction process is carried out continuously in the tubular reactor of ad hoc structure, the reaction system is stored up including raw material The difference in functionality such as tank, reaction zone, collection of products region;Channel of reactor structure includes:Pipe once-through type channel design, cake formula Pulse diameter varied narrow rectangular tube road structure, tiltedly side cake formula pulse diameter varied narrow rectangular tube road structure, enhancing mixed type cake formula square The flat pipeline configuration of shape, cardioid channel design.
CN201610972044.XA 2016-11-07 2016-11-07 Method for preparing 2,5-difluorobenzaldehyde through continuous oxidation of 2,5-difluorotoluene Pending CN106631727A (en)

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CN114618413A (en) * 2022-03-30 2022-06-14 江西炼石环保科技有限公司 Column type microchannel reactor

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US5473101A (en) * 1991-06-21 1995-12-05 Solvay Interox Limited Oxidation of alkylaromatics
CN102432448A (en) * 2011-11-07 2012-05-02 常州大学 Method for preparing acetophenone by oxidizing ethylbenzene in continuous flow micro-channel reactor
CN102516052A (en) * 2011-11-07 2012-06-27 常州大学 Method for preparing acetophenone through ethyl benzene oxidation by using microchannel reactor

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US5473101A (en) * 1991-06-21 1995-12-05 Solvay Interox Limited Oxidation of alkylaromatics
CN102432448A (en) * 2011-11-07 2012-05-02 常州大学 Method for preparing acetophenone by oxidizing ethylbenzene in continuous flow micro-channel reactor
CN102516052A (en) * 2011-11-07 2012-06-27 常州大学 Method for preparing acetophenone through ethyl benzene oxidation by using microchannel reactor

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* Cited by examiner, † Cited by third party
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CN114618413A (en) * 2022-03-30 2022-06-14 江西炼石环保科技有限公司 Column type microchannel reactor

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