CN106977383A - A kind of method for preparing citral - Google Patents
A kind of method for preparing citral Download PDFInfo
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- CN106977383A CN106977383A CN201710144184.2A CN201710144184A CN106977383A CN 106977383 A CN106977383 A CN 106977383A CN 201710144184 A CN201710144184 A CN 201710144184A CN 106977383 A CN106977383 A CN 106977383A
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/51—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition
- C07C45/511—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition involving transformation of singly bound oxygen functional groups to >C = O groups
- C07C45/513—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition involving transformation of singly bound oxygen functional groups to >C = O groups the singly bound functional group being an etherified hydroxyl group
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/61—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups
- C07C45/67—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton
Abstract
The present invention provides a kind of method for preparing citral, comprises the following steps：The dimethyl butadiene ether of cis/trans isopentene group 3 occurs Claisen and reset, and obtains the hexadiene of 2,4,4 trimethyl, 3 formoxyl 1,5, and Cope rearrangements are carried out afterwards and obtain citral (aldehyde of 3,72,6 octadiene of dimethyl 1).The method includes adding esters in the feed as side reaction inhibitor and plays a part of adjusting reaction rate.This method selectivity is high, and reaction rate is fast, and the whole flow process residence time is 1~15min.
Description
Technical field
The present invention relates to a kind of method for preparing citral.Using cis/trans-isopentene group -3- dimethyl butadienes ether as
Claisen rearrangement reactions occur for raw material, obtain 2,4,4- trimethyl -3- formoxyl -1,5- hexadienes, and Cope rearrangements are carried out afterwards
Obtain citral (3,7- dimethyl -2,6- octadiene -1- aldehyde).
Background technology
Citral is not only a kind of conventional fragrance product in itself, and is alternatively arranged as a variety of fine chemicals raw materials.Its
Downstream product just includes vitamin, rare spice etc..It is related to prepare production in the middle of citral in US publication US4288636
The introduction of thing cis/trans-isopentene group -3- dimethyl butadiene ethers, using prenol contracting isoamyl olefine aldehydr it is hot cracked after
To a molecule isopentene group -3- dimethyl butadienes ether and a molecule prenol, constantly prenol is steamed and obtains cis/anti-
Formula-isopentene group -3- dimethyl butadiene ethers.Cis/trans-isopentene group -3- dimethyl butadienes ether is again by rearrangement reaction
Citral can be prepared.But polymerization easily occurs for cis/trans-isopentene group -3- dimethyl butadienes ether instead at relatively high temperatures
Answer and experimental verification accessory substance prenol can be reset with cis/trans-isopentene group -3- dimethyl butadiene ethers Claisen
Condensation reaction occurs for reaction product 2,4,4- trimethyls -3- formoxyls -1,5- hexadiene and citral, influences ultimate yield.
It is described to prepare citral in publication WO2008037693 and optimizes, by cis/trans-iso-amylene
Product isopentene group -3- dimethyl butadienes ether and prenol steam to shorten simultaneously after the cracking of base -3- dimethyl butadiene ethers
Cis/trans-isopentene group -3- dimethyl butadiene ether heated times, afterwards both separated by rectifying, it is but suitable in actual production
The prenol that formula/trans-isopentene group -3- dimethyl butadienes ether is not all isolated generally with part.Again with cis/anti-
Formula-isopentene group -3- dimethyl butadienes ether is that raw material obtains citral by two step rearrangement reactions.But what the method was still suffered from lacks
Falling into is：1st, rearrangement process very exothermic, General reactions device is difficult to remove in reaction heat, actual production process to be also easy to produce safe thing
Therefore.When the 2nd, containing alcohols in system, have obvious side reaction and occur.And react general to react more than 150 DEG C, it reacts
Time is generally 20~40min, selectivity 90%~97%, and the reaction time is longer, and selectivity of product is lower.
Therefore need to seek a kind of preparation method of new citral, improve the selectivity and reaction rate of product.
The content of the invention
This patent purpose is a kind of method for preparing citral of offer, and this method selectivity is high, and reaction rate is fast.
In order to realize above goal of the invention, the technical solution adopted by the present invention is as follows：
A kind of method for preparing citral, is suppressing by raw material of cis/trans-isopentene group -3- dimethyl butadienes ether
2,4,4- trimethyl -3- formoxyl -1,5- hexadienes are obtained by Claisen rearrangement reactions in the presence of agent, Cope is carried out afterwards
Rearrangement reaction obtains citral (3,7- dimethyl -2,6- octadiene -1- aldehyde).Cis/trans-isopentene group -3- methyl fourth two
Alkene ether refers to cis-isopentene group -3- dimethyl butadienes ether and trans-isopentene group -3- dimethyl butadiene ethers.
In the present invention, the inhibitor is esters, and particularly big hindered alcohols derive esters, and the preferably tert-butyl alcohol derives esters
And/or triphenylcarbinol derives esters, more preferably t-butyl formate, tert-butyl acetate, the senecioic acid tert-butyl ester, formic acid triphen first
One or more in ester, the benzene methyl of acetic acid three and the benzene methyl of senecioic acid three, still more preferably t-butyl formate and/or first
Triphenyl phosphate methyl esters.Based on the mole for the raw material for treating rearrangement reaction, the inhibitor consumption is 0.02mol%~10mol%, excellent
Select 0.5mo1%~5mo1%.
In the present invention, main side reaction is due to the presence of a small amount of alcohols (predominantly prenol) in reaction raw materials, is contained
Measure as 0.1wt%~20wt%, based on reaction raw materials gross weight.Alcohols and raw material or intermediate product reaction generation hemiacetal and acetal
It is also one of side reaction additionally, due to having polymerization under multiple double bonds, double bond high temperature in raw molecule Deng accessory substance.The esters
With the effect for suppressing side reaction, reason is that with alcohols ester exchange reaction can occur for esters, generates new alcohols with bigger
Steric hindrance so that side reaction it is more difficult occur.Other esters also reduce carbon radicals in system, the concentration of carbonium ion plasma,
Slow down the generation of polymerisation to a certain extent.By the selection that final product is significantly improved from currently preferred esters
Property, 99% is reached as high as, and make it that reaction is gentle, it is easy to control.
As a kind of perferred technical scheme, it is a kind of to utilize microreactor and micro- heat exchanger system or micro- heat exchanger system system
The method of standby citral, using microreactor and micro- heat exchanger system heat and mass transfer enhancement and adds (side reaction) inhibitor,
So that cis/trans-isopentene group -3- dimethyl butadienes ether occurs that Claisen is reset and Cope is reset so that quickly, Gao Xuan
Selecting property obtains citral.
In the present invention, the microreactor and micro- heat exchanger system used, or micro- heat exchanger system and traditional reactor phase
Than microreactor and channel size of micro- heat exchanger itself are in micron to grade, with bigger specific surface area and smaller body
Product.Under the premise of more preferable mixed effect is ensured, bigger specific surface area, which ensure that, preferably moves thermal effect；Smaller volume makes
Reaction solution small volume in equipment is obtained, so as to reduce accident risk.
In the present invention, described microreactor and micro- heat exchanger system by feed pump, preheating pipeline, microreactor, micro- change
Hot device, delay pipeline composition, micro- heat exchanger system are made up of feed pump, preheating pipeline, micro- heat exchanger, delay pipeline.Reaction stream
Cheng Shi：Raw material enters preheating pipeline via feed pump, material liquid and inhibitor after preheating simultaneously, be pumped into microreactor respectively,
Entered after microreactor is sufficiently mixed short stay in micro- heat exchanger, or the mixed liquor after preheating is directly entered micro- heat exchange
Device.Micro- heat exchanger enters delay line sections after most of reaction heat is removed, when delay line sections keep certain temperature and stopped
Between after reaction solution by relief valve pressure release and cool down after enter product storage tank in.The feed pump feed rate is 1~100mL/
Min, proof pressure is 0.1~15MPa (absolute pressure).Preheating length of pipeline is 0.5~20m, and internal diameter is 1~8mm.Micro- reaction
Device flow is 0.5~70mL/min, and proof pressure is 0.1~3MPa (absolute pressure), 0.1~5s of residence time.Micro- heat exchanger
Flow is 0.5~50mL/min, and proof pressure is 0.1~50MPa (absolute pressure), and the residence time is 0.1~60s.Delay pipe
Line length is 0.5~100m, and internal diameter is 1~8mm.
In the present invention, preheating pipeline exterior constant temperature circulating bath temperature is constant temperature circulating outside 150~220 DEG C, microreactor
Bath temperature is 180~300 DEG C, and constant temperature circulating bath temperature is 120~180 DEG C outside micro- heat exchanger, and delay pipeline exterior constant temperature is followed
Ring bath temperature is 150~220 DEG C.The whole reaction process residence time is 1~15min, preferably 4~8min.
In the present invention, inhibitor uses and is pumped into microreactor and micro- heat exchanger simultaneously, respectively with the raw material after preheating, or micro-
The mode of heat exchanger is added.The reason for using this mode is：The preheated rear reaction rate of raw material is substantially accelerated, and heat release is violent, this
When the inhibitor that is pumped into absorb partial reaction heat, in addition we have found that the inhibitor added, which has, slows down reaction rate, reduce
The effect of exothermic peak.Its reason is that Claisen rearrangement reactions occur first for raw material, and there is intramolecular itself electron withdraw group to have
Beneficial to the generation of reaction, the ester inhibitors especially t-butyl formate and the benzene methyl of formic acid three of addition have disperseed in raw molecule
The electronegativity of portion's oxygen atom, reduces its cloud density, therefore slow down reaction rate so that reaction can be controlled preferably.
In the present invention, reaction raw materials be cis/trans-isopentene group -3- dimethyl butadiene ethers, or concentration be 10wt%~
99wt% cis/trans-isopentene group -3- dimethyl butadiene ethereal solutions, preferably cis/trans-isopentene group -3- methyl fourths
Diene ether.
In the present invention, the solvents of described cis/trans-isopentene group -3- dimethyl butadiene ethereal solutions for not with raw material
Inert aliphatic race alkane, aromatic hydrocarbons, ethers, halogenated alkane for reacting etc., such as normal heptane, toluene, 1,2- dichloroethanes, 1,
4- dioxane etc..
In the present invention, cis/trans-isopentene group -3- dimethyl butadiene ether structures formula is (Ia) and (Ib), 2,4,4- tri-
Methyl -3- formoxyl -1,5- hexadienes structural formula is (II), citral (3,7- dimethyl -2,6- octadiene -1- aldehyde) structural formula
For (III).
The positive effect of the present invention is：The present invention provides a kind of high selectivity, the quick method for preparing citral, in original
Specific ester is added in material as side reaction inhibitor and plays a part of adjusting reaction rate.By the selection to inhibitor and
The optimization of reaction condition (mainly charging sequence) significantly improves the selectivity of product.Selectivity reaches 95%~99%, preferably
97%~99%, the reaction time shortens to 1~15min.It is preferred that scheme in whole process in microreactor and/or micro- heat exchanger
Carried out in system, heat and mass transfer enhancement effect, so as to further shorten the whole reaction time, the reaction time shortens to 4~8min,
Shorten the side reaction time.
Embodiment
The following examples will be further described to method provided by the present invention, but the invention is not restricted to listed
The embodiment gone out, should also be included in other any known changes in scope of the presently claimed invention.
Gas chromatograph：Agilent7820A, chromatographic column HP-5 (30m × 0.25 μm of 320 μ m), injector temperature：150
℃；Split ratio 50:1；Carrier gas flux：1.5ml/min；Heating schedule：40 DEG C of holding 1min, 90 DEG C are warming up to 10 DEG C/min,
0min is kept, then 160 DEG C are warming up to 5 DEG C/min, 0min is kept, 280 DEG C, holding are then warming up to 30 DEG C/min
6min.Detector temperature：280℃.
Microreactor and micro- heat exchanger：Dalian Wei Kai Chemical Co., Ltd.s buy.
Microreactor model：CPMM-R300-so
Micro- heat exchanger model：HX204
The preparation of 1 cis/trans of embodiment-isopentene group -3- dimethyl butadiene ethers
By 774g prenols (about 9mol) and 84g isoamyls olefine aldehydr (about 1mol) and 1.15g phosphoric acid (mass content 85%,
About 0.01mol) add in tower bottom of rectifying tower, 9 pieces of rectifying column number of theoretical plate, 110 DEG C of column bottom temperature, top vacuum degree 5KPa, return
Stream is than being 1：10, after overhead extraction prenol and water, tower reactor heating 5h, when tower top is almost without backflow, stop heating.Tower reactor
Product is obtained for prenol contracting isoamyl olefine aldehydr, vapor detection acetal content 99%.Tower reactor is warming up to 150 DEG C, top vacuum
2KPa is spent, reflux ratio is 1：3, in overhead extraction cis/trans-isopentene group -3- dimethyl butadienes ether and prenol.By tower
Liquid vacuum distillation is pushed up, vacuum distillation is outer warm 90 DEG C, and pressure is 200Pa, steams prenol, obtains cis/trans-iso-amylene
Base -3- dimethyl butadiene ethers, the content of wherein prenol is 2.5%.
Embodiment 2
Microreactor preheating length of tube is 0.5m, and internal diameter is 1mm, and preheating pipeline exterior constant temperature circulating bath temperature is 180 DEG C.
Constant temperature circulating bath temperature is 200 DEG C outside microreactor, and constant temperature circulating bath temperature is 120 DEG C outside micro- heat exchanger.Be delayed pipeline
Length is 6m, and internal diameter is 4mm.The pipeline exterior constant temperature circulating bath temperature that is delayed is 180 DEG C.By raw material (cis/trans-iso-amylene
Base -3- dimethyl butadiene ethers mass content 97%, the content of prenol is 2.5%) to be passed through in advance with the charging of 15mL/min speed
Hot pipeline, t-butyl formate with raw material 0.5mo1% amount and raw material simultaneously, be pumped into microreactor respectively, flow through micro- heat exchanger and
Being delayed, (pressure will be 0.15MPa to pipeline after micro- heat exchanger, and reaction solution is respectively 4s in microreactor and micro- heat exchanger residence time
And 60s).Sampled after system stable operation 2h.Feed stock conversion 85%, selectivity 97%, reaction time 8min.
Embodiment 3
Micro- heat exchanger preheating length of tube is 0.5m, and internal diameter is 1mm, and preheating pipeline exterior constant temperature circulating bath temperature is 200 DEG C,
It is 150 DEG C that reaction solution, which is directly entered constant temperature circulating bath temperature outside micro- heat exchanger, micro- heat exchanger,.Delay length of pipeline is 6m, interior
Footpath is 4mm.The pipeline exterior constant temperature circulating bath temperature that is delayed is 180 DEG C.By raw material (cis/trans-isopentene group -3- methyl fourths
Diene ether mass content 97%, the content of prenol is 2.5%) to be fed with 20mL/min speed by preheating pipeline, acetic acid
The tert-butyl ester is pumped into micro- heat exchanger simultaneously, respectively with raw material 2.0mo1% amount and raw material, and the rear delay pipeline that enters is (after micro- heat exchanger
Pressure will be 0.2MPa, and reaction solution is respectively 3s and 45s in microreactor and micro- heat exchanger residence time).System stable operation
Sampled after 2h.Feed stock conversion 95%, selectivity 95%, reaction time 6min.
Embodiment 4
Microreactor preheating length of tube is 1.0m, and internal diameter is 1mm, and preheating pipeline exterior constant temperature circulating bath temperature is 220 DEG C.
Constant temperature circulating bath temperature is 250 DEG C outside microreactor, and constant temperature circulating bath temperature is 150 DEG C outside micro- heat exchanger.Be delayed pipeline
Length is 6m, and internal diameter is 4mm.The pipeline exterior constant temperature circulating bath temperature that is delayed is 180 DEG C.By raw material (cis/trans-iso-amylene
Base -3- dimethyl butadiene ethers mass content 19%, the content of prenol is 0.5%, and retarder thinner is normal heptane, normal heptane matter
Amount content 79%) fed with 30mL/min speed by preheating pipeline, the senecioic acid tert-butyl ester is with raw material 10mo1% amount and original
Material simultaneously, be pumped into microreactor respectively, pass sequentially through microreactor, micro- heat exchanger and delay pipeline (after micro- heat exchanger pressure will
For 0.3MPa, reaction solution is respectively 2s and 30s in microreactor and micro- heat exchanger residence time).Taken after system stable operation 2h
Sample.Feed stock conversion 93%, selectivity 98%, reaction time 4min.
Embodiment 5
Microreactor preheating length of tube is 0.5m, and internal diameter is 1mm, and preheating pipeline exterior constant temperature circulating bath temperature is 180 DEG C.
Constant temperature circulating bath temperature is 250 DEG C outside microreactor, and constant temperature circulating bath temperature is 170 DEG C outside micro- heat exchanger.Be delayed pipeline
Length is 3m, and internal diameter is 4mm.The pipeline exterior constant temperature circulating bath temperature that is delayed is 200 DEG C.By raw material (cis/trans-iso-amylene
Base -3- dimethyl butadiene ethers mass content 97%, the content of prenol is 2.5%) to be passed through in advance with the charging of 15mL/min speed
Hot pipeline, the benzene methyl of formic acid three with raw material 3.0mo1% amount and raw material simultaneously, be pumped into microreactor respectively, pass sequentially through micro- anti-
Answering device, micro- heat exchanger and delay pipeline, (pressure will be 0.15MPa after micro- heat exchanger, and reaction solution is in microreactor and micro- heat exchanger
Residence time is respectively 4s and 60s).Sampled after system stable operation 2h.Feed stock conversion 99.9%, selectivity 99%, reaction
Residence time 5min.
Embodiment 6
Microreactor preheating length of tube is 0.5m, and internal diameter is 1mm, and preheating pipeline exterior constant temperature circulating bath temperature is 180 DEG C.
Constant temperature circulating bath temperature is 250 DEG C outside microreactor, and constant temperature circulating bath temperature is 150 DEG C outside micro- heat exchanger.Be delayed pipeline
Length is 12m, and internal diameter is 4mm.The pipeline exterior constant temperature circulating bath temperature that is delayed is 200 DEG C.By raw material (cis/trans-iso-amylene
Base -3- dimethyl butadiene ethers mass content 97%, the content of prenol is 2.5%) to be passed through in advance with the charging of 50mL/min speed
Hot pipeline, the benzene methyl of senecioic acid three with raw material 5.0mo1% amount and raw material simultaneously, be pumped into microreactor respectively, pass sequentially through
(pressure will be 0.45MPa after micro- heat exchanger, and reaction solution is in microreactor and micro- changes for microreactor, micro- heat exchanger and delay pipeline
The hot device residence time is respectively 1.2s and 18s).Sampled after system stable operation 2h.Feed stock conversion 97%, selectivity 97%,
Reaction time 5min.
Embodiment 7
Microreactor preheating length of tube is 1.0m, and internal diameter is 1mm, and preheating pipeline exterior constant temperature circulating bath temperature is 220 DEG C.
Constant temperature circulating bath temperature is 270 DEG C outside microreactor, and constant temperature circulating bath temperature is 160 DEG C outside micro- heat exchanger.Be delayed pipeline
Length is 6m, and internal diameter is 4mm.The pipeline exterior constant temperature circulating bath temperature that is delayed is 220 DEG C.By raw material (cis/trans-iso-amylene
Base -3- dimethyl butadiene ethers mass content 98%, the content of prenol is 1.5%) to be passed through in advance with the charging of 35mL/min speed
Hot pipeline, t-butyl formate is pumped into microreactor, micro- heat exchanger and delay simultaneously, respectively with raw material 2.0mo1% amount and raw material
Pipeline (after micro- heat exchanger pressure will be 0.32MPa, reaction solution microreactor and micro- heat exchanger residence time be respectively 1.7s and
26s).Sampled after system stable operation 2h.Feed stock conversion 99.5%, selectivity 98%, reaction time 4min.
Embodiment 8
Tubular reactor is placed in reactor oil bath and carries out being heated to 210 DEG C, reactor rotating speed is strengthened for 500r/min
Heat transfer, coil pipe external diameter 8mm, internal diameter is 6mm, common 10m.Reaction solution outlet carries out chilling using condensed water.By the benzene methyl of formic acid three
With raw material, (cis/trans-isopentene group -3- dimethyl butadiene ethers mass content 98%, 1.5%) content of prenol is
1.5mo1% amount takes after passing through tubular reactor, system stable operation 2h after being mixed with raw material with the charging of 50mL/min speed
Sample.Feed stock conversion 79.5%, selectivity 95%, reaction time 23min.
Comparative example 1 (is contrasted) with embodiment 2
Microreactor preheating length of tube is 0.5m, and internal diameter is 1mm, and preheating pipeline exterior constant temperature circulating bath temperature is 180 DEG C.
Constant temperature circulating bath temperature is 200 DEG C outside microreactor, and constant temperature circulating bath temperature is 120 DEG C outside micro- heat exchanger.Be delayed pipeline
Length is 6m, and internal diameter is 4mm.The pipeline exterior constant temperature circulating bath temperature that is delayed is 180 DEG C.By raw material (cis/trans-iso-amylene
Base -3- dimethyl butadiene ethers mass content 97%, the content of prenol is 2.5%) to be passed through in advance with the charging of 15mL/min speed
Hot pipeline, then be pumped into microreactor, flowing through micro- heat exchanger and delay pipeline, (pressure will be 0.15MPa, reaction solution after micro- heat exchanger
It is respectively 4s and 60s in microreactor and micro- heat exchanger residence time).Sampled after system stable operation 2h.Feed stock conversion
89%, selectivity 91%, reaction time 8min.
Comparative example 2 (is contrasted) with implementing 6
Microreactor preheating length of tube is 0.5m, and internal diameter is 1mm, and preheating pipeline exterior constant temperature circulating bath temperature is 180 DEG C.
Constant temperature circulating bath temperature is 250 DEG C outside microreactor, and constant temperature circulating bath temperature is 150 DEG C outside micro- heat exchanger.Be delayed pipeline
Length is 12m, and internal diameter is 4mm.The pipeline exterior constant temperature circulating bath temperature that is delayed is 200 DEG C.By the benzene methyl of senecioic acid three with original
Expect 5.0mo1% amount and raw material (cis/trans-isopentene group -3- dimethyl butadiene ethers mass content 97%, prenol
Content is by preheating pipeline, then to pass sequentially through microreactor, micro- heat exchanger after 2.5%) mixing with the charging of 50mL/min speed
And (pressure will be 0.45MPa to delay pipeline after micro- heat exchanger, and reaction solution is respectively in microreactor and micro- heat exchanger residence time
1.2s and 18s).Sampled after system stable operation 2h.Feed stock conversion 91%, selectivity 94%, reaction time 5min.
Comparative example 3 (is contrasted) with embodiment 8
Tubular reactor is placed in reactor oil bath and carries out being heated to 210 DEG C, reactor rotating speed is strengthened for 500r/min
Heat transfer, coil pipe external diameter 8mm, internal diameter is 6mm, common 10m.Reaction solution outlet carries out chilling using condensed water.Raw material is (cis/anti-
Formula-isopentene group -3- dimethyl butadiene ethers mass content 98%, the content of prenol is 1.5%) to be entered with 50mL/min speed
Material passes through to be sampled after tubular reactor, system stable operation 2h.Feed stock conversion 85.7%, selectivity 89%, when reaction is stopped
Between 23min.
Claims (10)
1. a kind of method for preparing citral, it is characterised in that using cis/trans-isopentene group -3- dimethyl butadienes ether as original
Material is reset in the presence of the inhibitors by Claisen and Cope rearrangement reactions obtain citral.
2. according to the method described in claim 1, it is characterised in that the inhibitor is esters, preferably big hindered alcohols derived ester
Class, the more preferably tert-butyl alcohol derive esters and/or triphenylcarbinol and derive esters, further preferred t-butyl formate, tert-butyl acetate,
One or more in the senecioic acid tert-butyl ester, the benzene methyl of formic acid three, the benzene methyl of acetic acid three and the benzene methyl of senecioic acid three.
3. method according to claim 1 or 2, it is characterised in that the mole based on reaction raw materials, the inhibitor is used
Measure as 0.02mol%~10mol%, preferably 0.5mo1%~5mo1%.
4. the method according to claim any one of 1-3, it is characterised in that rearrangement reaction is in microreactor and micro- heat exchanger
System is carried out, or is carried out in micro- heat exchanger system.
5. method according to claim 4, it is characterised in that microreactor and micro- heat exchanger system are by feed pump, preheating
Pipeline, microreactor and micro- heat exchanger, delay pipeline composition；Described micro- heat-exchange system is by feed pump, preheating pipeline, micro- heat exchange
Device, delay pipeline composition；Raw material enters preheating pipeline via feed pump, and raw material and inhibitor after preheating are pumped into simultaneously, respectively
Microreactor, is pumped into micro- heat exchanger subsequently into the raw material and inhibitor after micro- heat exchanger, or preheating, mixes afterwards simultaneously, respectively
Close liquid and enter delay line sections, reaction solution finally obtains product from delay pipeline outflow.
6. method according to claim 5, it is characterised in that：It is 150~220 to preheat pipeline exterior constant temperature circulating bath temperature
DEG C, constant temperature circulating bath temperature is 180~300 DEG C outside microreactor, outside micro- heat exchanger constant temperature circulating bath temperature be 120~
180 DEG C, delay pipeline exterior constant temperature circulating bath temperature is 150~220 DEG C.
7. method according to claim 5, it is characterised in that：The whole reaction process residence time is 1~15min, preferably 4
~8min.
8. according to the method described in claim 1, it is characterised in that：Reaction raw materials cis/trans-isopentene group -3- methyl fourths
The content of prenol is 0.1wt%~20wt% in diene ether, based on raw material gross weight.
9. the method according to claim 1 or 8, it is characterised in that：Described cis/trans-isopentene group -3- methyl fourths
Diene ether is cis/trans-isopentene group -3- dimethyl butadiene ethereal solutions that concentration is 10wt%~99wt%.
10. method according to claim 9, it is characterised in that：Described cis/trans-isopentene group -3- methyl fourth two
The solvent of alkene ethereal solution is the inert aliphatic race alkane not reacted with cis/trans-isopentene group -3- dimethyl butadiene ethers
In one or more in hydrocarbon, aromatic hydrocarbons, ethers, alkyl halide, preferably normal heptane, toluene, 1,2- dichloroethanes, Isosorbide-5-Nitrae-dioxane
One or more.
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| CN111018682A (en) * | 2019-12-17 | 2020-04-17 | 南通天泽化工有限公司 | Preparation method of citral |
| CN111807936A (en) * | 2020-07-22 | 2020-10-23 | 万华化学集团股份有限公司 | Preparation method of prenyl isopentenyl ether |
| CN112225655A (en) * | 2020-09-10 | 2021-01-15 | 万华化学集团股份有限公司 | Preparation method of citral |
| CN112574018A (en) * | 2020-11-30 | 2021-03-30 | 万华化学集团股份有限公司 | Low-color-number citral and preparation method thereof |
| CN112574015A (en) * | 2020-12-11 | 2021-03-30 | 万华化学集团股份有限公司 | Method for preparing cyclocitral from C10 unsaturated aldehyde rectifying tower bottoms |
| CN114133321A (en) * | 2021-12-06 | 2022-03-04 | 万华化学集团股份有限公司 | Preparation method of citral |
| CN114773168A (en) * | 2022-04-28 | 2022-07-22 | 江苏宏邦化工科技有限公司 | Method for synthesizing cis/trans-prenyl-3-methyl butadiene ether by using methyl butynol and isopentenol |
| CN115160113A (en) * | 2022-07-06 | 2022-10-11 | 江苏宏邦化工科技有限公司 | Method for simultaneously synthesizing two citral intermediates |
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| US4288636A (en) * | 1979-06-30 | 1981-09-08 | Basf Aktiengesellschaft | Preparation of citral |
| CN1255480A (en) * | 1998-10-07 | 2000-06-07 | Basf公司 | Process for preparing citral |
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| US4288636A (en) * | 1979-06-30 | 1981-09-08 | Basf Aktiengesellschaft | Preparation of citral |
| CN1255480A (en) * | 1998-10-07 | 2000-06-07 | Basf公司 | Process for preparing citral |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111018682A (en) * | 2019-12-17 | 2020-04-17 | 南通天泽化工有限公司 | Preparation method of citral |
| CN111807936A (en) * | 2020-07-22 | 2020-10-23 | 万华化学集团股份有限公司 | Preparation method of prenyl isopentenyl ether |
| CN111807936B (en) * | 2020-07-22 | 2022-11-08 | 万华化学集团股份有限公司 | Preparation method of prenyl isopentenyl ether |
| CN112225655A (en) * | 2020-09-10 | 2021-01-15 | 万华化学集团股份有限公司 | Preparation method of citral |
| CN112225655B (en) * | 2020-09-10 | 2024-02-27 | 万华化学集团营养科技有限公司 | Preparation method of citral |
| CN112574018A (en) * | 2020-11-30 | 2021-03-30 | 万华化学集团股份有限公司 | Low-color-number citral and preparation method thereof |
| CN112574018B (en) * | 2020-11-30 | 2022-07-12 | 万华化学集团股份有限公司 | Low-color-number citral and preparation method thereof |
| CN112574015A (en) * | 2020-12-11 | 2021-03-30 | 万华化学集团股份有限公司 | Method for preparing cyclocitral from C10 unsaturated aldehyde rectifying tower bottoms |
| CN114133321A (en) * | 2021-12-06 | 2022-03-04 | 万华化学集团股份有限公司 | Preparation method of citral |
| CN114773168A (en) * | 2022-04-28 | 2022-07-22 | 江苏宏邦化工科技有限公司 | Method for synthesizing cis/trans-prenyl-3-methyl butadiene ether by using methyl butynol and isopentenol |
| CN115160113A (en) * | 2022-07-06 | 2022-10-11 | 江苏宏邦化工科技有限公司 | Method for simultaneously synthesizing two citral intermediates |
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