JPH03261775A - Production of 2-hyroxytetrahydrofuran - Google Patents

Abstract

PURPOSE:To profitably obtain the subject compound useful as a raw material for a solvent and polymer, etc., by subjecting allyl alcohol to a hydroformylation reaction in the presence of a rhodium complex, etc., in an organic solvent, etc. CONSTITUTION:Allyl alcohol is subjected to a hydroformylation reaction with hydrogen and CO in the presence of a rhodium complex and a tri-substituted phosphine in an organic solvent, and the reaction product and the unreacted raw materials are extracted from the reaction mixture solution with an aqueous solvent. The extraction residue containing the catalyst components is circulated in the hydroformylation reaction process. The extract solution containing the reaction product and the unreacted reaction raw materials is distilled under vacuum so as to distill out 2-hydroxy-tetrahydrofuran at a temperature of <=60 deg.C, thereby providing the 2-hydroxytetrahydrofuran.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an industrially advantageous method for producing F12-hydroxytetrahydrofuran.

γ-butyrolactone is obtained, and 2.3 is obtained by dehydration reaction.
- Gives dihydrofuran. 2.3-Dihydrofuran can be cationically polymerized to give a polymer compound with a tetrahydro-7-lane skeleton 't1r that can be used for various industrial purposes, and hydrogenated to give tetrahydrofuran, which is useful as a solvent, a raw material for polymer compounds, etc. give.

[Conventional technology]

2-Hydroxytetrahydrofuran is obtained by subjecting allyl alcohol to a hydroformylation reaction in the presence of a rhodium complex compound catalyst, and distilling and separating 4-hydroxybutyraldehyde from the total reaction mixture.
It is known that 2-hydroxytetrahydrofuran can be obtained by mixing 2-hydroxytetrahydrofuran with an intramolecular acetal compound (see US Pat. No. 4,129,579) [Problems to be Solved by the Invention] Production of the above-mentioned 2-hydroxytetrahydrofuran The method has several problems to be solved and is extremely difficult to implement industrially. That is, in the method of distilling and separating 2- and toxytetrahydrofuran from the reaction mixture after the hydroformylation reaction, the product is separated when the allyl alcohol hydroformylation reaction mixture is heated in the presence of a catalyst. Because it is easily decomposed, when trying to isolate 2-hydroxytetrahydrofuran by direct distillation from the allyl alcohol hydroformylation reaction mixture, the a*fli yield decreases significantly (%
(Refer to Publication No. 51-29412).

Further, according to the inventor's practice, it has been found that the activity of the rhodium catalyst decreases significantly after being subjected to a distillation operation, making it impossible to recycle and reuse the catalyst. This means that the above-mentioned method for converting 2-hydroxytetrahydrofuran into IJ4 is not industrially viable since the rhodium catalyst is extremely expensive. Therefore, a method has been proposed in which the hydroformylation reaction product of allyl alcohol is extracted and separated from the reaction mixture using an aqueous medium (
(See Japanese Unexamined Patent Publication No. 54-IU64U7). however.

2-Hydroxytetrahydro 7 run 2yohia J product 3-hydroxy-2-methylpropionaldehyde a Since it is thermally unstable, these compounds were subjected to a hydrogenation reaction to form the corresponding dihydroxyl compounds. Derol 1,4-butanediol>! and 2-methyl-1,3-
It is said that 2-hydroxytetrahydrofuran cannot be separated by distillation directly from the extract.The purpose of the present invention is to convert S2-hydroxytetrahydrofuran into an industrially advantageous product. The goal is to provide a method for manufacturing.

[Means for Solving Problem 1r] According to the present invention, the above object is achieved by subjecting allyl alcohol to a hydroformylation reaction with hydrogen and carbon monoxide in the presence of a rhodium complex compound and a trisubstituted phosphine in an organic solvent. Then, the reaction product and unreacted raw materials are extracted and separated from the hydroformylation reaction mixture in an aqueous medium, and the raffinate containing the catalytic acid is recycled and supplied to the hydroformylation reaction step.
2-% molding involves subjecting the extract containing the reaction product and unreacted raw materials to a distillation operation under reduced pressure so that 2-hydroxytetrahydrofuran is distilled out at a temperature of 60°C or less. This is accomplished by providing a method for producing hydroxytetrahydrofuran.

The rhodium complex compound used in the method of the present invention includes a human roformylation catalyst.

The rhodium complex R, which is insoluble or sparingly soluble in water, is a rhodium complex compound represented by an alkyl group or an aryl group. It's especially nice. As a typical rhodium complex compound.

HRh(Co) CP (C8H5)3 )3 , H
Examples include Rh (CO) CP (C6H4C)13)3]3. The rhodium complex compound is usually used in a concentration of 0.1 to 10 mmol per hydroformylation reaction solution 11. In an uninventive way.

Selectivity to 2-hydroxytetrahydrofuran.

From the viewpoint of minimizing loss of the rhodium complex compound into the extraction water and stabilizing the catalyst activity, it is preferable to coexist an excess amount of trisubstituted phosphine with respect to the dium complex compound in the reaction system. Generally, the trisubstituted phosphine is preferably added in a proportion of 10 to 300 mmol per mole of the rhodium complex compound. As a trisubstituted phosphine, lu-Bokuna FAA'a' (in the formula, A, A'j?
Tri-substituted phosphine represented by IL<, triphenylphosphine, trinaphthylphosphine and tritoIJ-ruphosphine are preferable because of their selectivity to 2-hydroxytetrahydrofuran and ease of availability. , preferred from the viewpoint of low solubility in water, catalytic activity, etc.

In the method of the present invention, in addition to the above trisubstituted phosphine, the following general formula (wherein R16 and R2 each represent an aryl group,
Q"h and Q2 each represent an aryl group or a saturated hydrocarbon group having 4 or more carbon atoms, and 2 is an alkylene group 't- whose straight chain portion has 2 to 5 carbon atoms and may be substituted with a methyl group. i) Diphosphinolucan represented by rhodium complex compound 1
The proportion ranges from 02 to 2.0 moles.

Preferably, it is present in a proportion in the range of 0.25 to 1.5 mol (9) because the life of the catalyst activity of the rhodium complex compound is significantly extended. Preferred diphosphinoalkanes include the following compounds.

(CsHs+2PCHzCHzP(C@)is)2.

Rs (CH3CsH4)2PCHzCHCHzP(CsH4
CH3)2, (C6Hs), PQizCF1201z
CHzP(Cs)is)2.

(Ce Hs)2PCH2CH2Q(2CH2CH2P
(C6H5n2.

13 (Co Hs)2PCHzC)iz CHQ12 CH
For 2P (CsHs)2hydroform, it is preferable to use an organic solvent that dissolves the rhodium complex compound and the trisubstituted phosphine and is difficult to miscible with water. Cyclic hydrocarbons are preferred.

The hydroformylation reaction of the present invention is carried out in the presence of a rhodium complex compound and a trisubstituted phosphine.

The temperature of the O reaction, which is carried out by supplying carbon monoxide and hydrogen gas in an organic solvent containing allyl alcohol in the coexistence of a diphosphinoalkane, is between room temperature and <rt.
It is preferably within the range of 120°C, particularly within the range of 40 to 80°C. The partial pressure ratio of hydrogen and carbon monoxide is preferably within the range of 1:2 to 5:1 based on the ratio of waste entering the reactor. The reaction pressure is preferably in the range of 0.5 to 2 () atmospheres. N in the reaction system
There is no problem even if a gas inert to the hydroformylation reaction, such as helium, helium, argon, or methane, coexists.

Industrially, the hydroformylation reaction is preferably carried out in a continuous manner in a stirred tube or column reaction tank.

At this time, it is preferable to set the supply rate and residence time of allyl alcohol so that the concentration of the product in the combined liquid in one reactor is 0.5 to 5 mol/j.

After the hydroformylation reaction, unreacted allyl alcohol and reaction products are extracted and separated from the reaction mixture using an aqueous medium, preferably water, and the raffinate layer (organic layer) containing the catalytic acid is recycled to the hydroformylation step. Feeding port Here, the aqueous medium means water or a homogeneous mixture of water and an organic solvent 1 such as methanol, ethanol, butanediol, etc. The volume ratio of the aqueous medium used for the extraction operation to the trz hydroformylation reaction mixture is preferably within the range of 0.5 to 2.0.

2-Hydroxytetra and dorofuran are separated from the extracted aqueous layer containing the reaction product by distillation.

In this case, the temperature of the distillation operation is below 0°C, more preferably at 55°C.
It is necessary to adjust the degree of vacuum so that 2-hydrokinetetrahydrofuran is distilled out at a temperature of 0.degree. C. or lower, and to carry out the reaction under reduced pressure. At temperatures higher than 60°C, some of the 2-hydroxytetrahydrofuran begins to decompose.

At temperatures below 60°C, such decomposition does not occur, and 2-hydroxytetrahydrofuran can be efficiently deposited.

As mentioned above, the hydroformylation reaction product of allyl alcohol is thermally unstable, and it is difficult to separate it by distillation to obtain a high yield of 2-hydroxytetrahydrofuran from the hydroformylation reaction mixture. It is possible to separate by distillation.

Before subjecting the extract with an aqueous medium to a distillation operation.

Extraction operation using an organic solvent that does not mix the extract with water lCf
It is also possible to separate r) 2-hydroxytetrahydrofuran by extracting 1L, 2-hydroxytetrahydrofuran with an ammonium solvent and subjecting the obtained extract to a distillation operation. In this case, it is necessary to adjust the reduced pressure It so that 2-hydroxytetrahydrofuran is distilled out at a temperature of %60°C or less, more preferably ri55°C or less. Since 2-hydroxytetrahydrofuran is separated by direct distillation from the extracted aqueous layer, the method of first extracting into an organic solvent and then subjecting the extraction limb to distillation is energy efficient because water with a large latent heat of vaporization is not evaporated. may be advantageous. Used in this case! Examples of solvents include aromatic hydrocarbons such as benzene, toluene and xylene, esters such as ethyl acetate and inflovir acetate, and ketones such as methyl ethyl ketone and methyl impropyl ketone.

Examples include ethers such as diptyl ether and dioctyl ether. The aqueous extraction layer and the organic solvent are used in a volume ratio of 1:5 to 5:1. Well, in this case, there is no need to properly refer to an organic solvent that has a boiling point difference with that of 2-hydroxytetra and dorofuran.

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples in any way.

Example 1 A hydroformylation reaction of allyl alcohol was carried out continuously according to the flow shown in FIG. Reactor (1) is a magnetically stirred reactor with an internal volume of 3.54 J, reactor (2) is a magnetically stirred reactor with an internal volume of 7.5 J, and an extraction column (8
) is filtered in a stirred extraction column with an internal volume of 2.2j.
k/j>! H(C6H5)2P(Q(2)4
P(C6H5).

0.5 mmol/4f The solution f obtained by dissolving in toluene
It was charged into the reactor (1) from the 13jt catalyst liquid storage tank (to). Allyl alcohol is supplied to the reactor (1) through the line (4) at a rate of 200117/hour, and the line (γ ) to the reactor (2) at 1.717 hours.
). The temperature of the reactor (1) was maintained at 60°C and the circular pressure was maintained at t-2.1 absolute atmospheric pressure, and the mixture was stirred at a speed of 570 rpm. Line (5) through the reactor (2 tons) with hydrogen gas at a rate of 24 ONJ/hour, and with carbon oxide t8ONJ
/ hour supplied. Output gas from the reactor (2) is transferred to the line (
6) t-0 reactor (1) fed to reactor (1) through
Output gas from the a-line (8) was discharged to the outside of the system through the t-line. The liquid volume of the reaction mixture in the reactor (2) was maintained at f near, 54, and the liquid volume of the reaction mixture was increased to 1.71/cm through the line (9).
It was sent to the extraction column (3) at a rate of 1 hour. The internal temperature of reactor (2) was set to 60°C.

The internal pressure was kept at 2.0 absolute atm and stirring was carried out at a speed of 800 rpm. Line (g)? :Through the extraction tower (8) 1
．． Water was supplied at a rate of 5 J/hour, and the extraction operation was performed at 30° C. under a hydrogen atmosphere. The extract containing the catalyst components after extraction was taken out.

After reaching a steady state, the concentration of allyl alcohol in the extracted aqueous layer was analyzed by gas chromatography, and the conversion rate of allyl alcohol was found to be 985. A hydrogenation reaction was carried out under conditions of 100 atmospheric pressure and 60°C using nickel as a catalyst on a part of the extracted aqueous layer, and 2-hydroxytetrahydrofuran was dissolved in 1.4-
After converting to butanediol, analysis by gas chromatography revealed that 1.3
It was determined that 7 moles of 2-hydroxytetrahydrofuran were present.

The extracted aqueous layer containing 2-hydroxytetrahydrofuran thus obtained was extracted with a 50Jfr ceramic Sluzer Brothe
(manufactured by rsLtd), inner diameter 100cm, column length 2080mm.
Vacuum distillation was carried out using a distillation apparatus equipped with a glass distillation column, and the degree of vacuum at the top of the column was 4.0 to 4.5 m) iF, and the temperature was 4.
5.71 KF of 2-hydroxytetrahydrofuran was obtained as a 2-47°C fraction.

Example 2 50jt of extracted aqueous layer obtained in Example 1 - i?
Then, vacuum distillation is performed in the same distillation equipment, and the degree of vacuum at the top of the column is 5.
゜υ~6.0-HP, 5 as a fraction with a temperature of 50-54℃
．． 65 and 4 of 2-hydroxytetrahydrofuran were obtained.

Example 3 The extracted aqueous layer obtained in Example 1 was transferred to the extraction tower (8
) through line QD at a rate of 0.85j/h to 1 reactor (2). Pensene was fed through line (9) as a t-liquid reservoir at a rate of 1.517j/h, and the extracted aqueous layer was heated at 30°C. Allyl alcohol P and reaction product in the tube were back extracted into the benzene layer. After reaching a steady state, when 50 J of the benzene layer of Example 1K was applied, vacuum distillation was carried out in the same distillation column, and the degree of vacuum at the top of the column was 3.5 to 4.0 ■H9, and the temperature was 38
2.80 Kl of 2-hydroxytetrahydrofuran was obtained as a fraction at ~42°C.

Ratio 4R Example 1 The extracted aqueous layer 50J' obtained in Example 1 was subjected to vacuum distillation using the same distillation apparatus as Example 1, and the degree of vacuum at the top of the column was t-
When maintained at 11 to 15 ■Hf, the temperature at the top of the tower was 11605
2-Hydroxytetrahydrofuran was distilled out at ~62°C, and the yield tj was 4.70 kg.

High boilers had accumulated at the bottom of the distillation equipment.

〔Effect of the invention〕

According to the present invention, 2-hydroxytetrahydrofuran can be produced industrially advantageously.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the flow used for the reaction in Example 1. 1.2...Reactor, 3...Extraction column, 4
~12... Line, 13... Catalyst liquid reservoir, 14a-e... Pump.

Claims (1)

[Claims] 1. Allyl alcohol is subjected to a hydroformylation reaction with hydrogen and carbon monoxide in the presence of a rhodium complex compound and a trisubstituted phosphine in an organic solvent, and the hydroformylation reaction mixture is reacted in an aqueous medium. The product and unreacted raw materials are extracted and separated, the raffinate containing the catalyst component is circulated and supplied to the hydroformylation reaction process, and 2-hydroxytetrahydrofuran is extracted from the extract containing the reaction product and unreacted raw material at a temperature of 60°C or less. A method for producing 2-hydroxytetrahydrofuran, which comprises subjecting the extract to a distillation operation under reduced pressure so as to distill it out. 2. From the extract containing the reaction product and unreacted raw materials, 2-
Hydroxytetrahydrofuran is extracted and separated using an organic solvent that is immiscible with water, and the resulting extract is subjected to a distillation operation under reduced pressure so that 2-hydroxytetrahydrofuran is distilled out at a temperature of 60°C or less. The method for producing 2-hydroxytetrahydrofuran according to claim 1.