JPS6019781A - Production of 2-hydroxy-4-methyltetrahydropyrane - Google Patents

Abstract

PURPOSE:To produce the titled compound economically in an industrial scale, by hydroformylating 3-methyl-3-buten-1-ol with hydrogen and carbon monoxide in the presence of a rhodium complex compound catalyst, extracting the reaction product with water or an aqueous mixture, and recycling the extraction residue as the catalyst solution. CONSTITUTION:3-Methyl-3-buten-1-ol is hydroformulated with the gaseous mixture of hydrogen and carbon monoxide in a solvent comprising an aliphatic hydrocarbon, alicyclic hydrocarbon, or a mixture of aromatic hydrocarbon and aliphatic hydrocarbon or alicyclic hydrocarbon, in the presence of a rhodium complex compound [e.g. Rh6(CO)16] (0.01-0.5mg-atom/1 in terms of Rh atom) and a trisubstituted phosphine (e.g. triphenylphosphine) (0.01-10m-mol/l). The reaction mixture is extracted with water or a mixture of water and a polyhydric alcohol (e.g. ethylene glycol), and the extraction residue is recycled as the catalyst solution to the hydroformylation reaction zone.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for the preparation of 2-hydroxy-4-methyltetrahydrobilane by hydroformylation of 3-methyl-5-buten-1-ol.

It is already known that 2-hydroxy-4-methyltetrahydrobilane is produced by the hydroformylation reaction of 3-methyl-3-buten-1-ol using a rhodium complex compound as a catalyst (Japanese Patent Application Laid-Open No. 5O-10iS910). (see official bulletin). However, when attempting to produce 2-hydroxy-4-methyltetrahydrobilane on an industrial scale using this reaction, the rhodium complex compound must be circulated for a long period of time since rhodium amalgamation is expensive due to its single axis. There is a need to reuse the product, and for this purpose, it is essential to efficiently separate the product and the catalyst acid without reducing the catalyst activity.
No. 1'0 discloses the 2-hydroxy-
It only shows that 4-methyltetrahydrobilane is separated and obtained from the reaction mixture by a normal distillation operation, and does not mention the possibility of recycling the catalyst.1. Rhodium complex compounds are generally relatively thermally unstable, and when the hydroformylation product is separated from the reaction mixture by ordinary distillation after the hydroformylation reaction, the rhodium lead compound is partially thermally altered. However, there is a concern that the catalytic activity will decrease (Japanese Patent Laid-Open No. 1986-
In order to improve this point, it was proposed to coexist a specific amount of a disubstituted small sphine oxide in addition to a rhodium complex compound in the hydroformylation reaction of 5-methyl-3-buten-1-ol. (Refer to Japanese Patent Laid-Open No. 55-45642). Although the proposed method does improve the thermal stability of the rhodium complex, it is difficult to maintain stability over a long period of time because the product, 2-hydroxy-4-methyltetrahydrobilane, is relatively thermally unstable. During the reaction period, there is concern that a portion of the rhodium-lead compound may be lost when the polycondensate of ζζ2-hydroxy-4-methyltetrahydrobilane is reacted and separated.

Extraction methods have also been proposed as a method for separating products and catalyst components in the hydroformylation reaction of certain persimmon olefinic compounds without using the steam whistle method. For example, a method is known in which allyl alcohol or vinyl acetate is hydroformylated in the presence of a rhodium complex compound and an excess amount of trisubstituted phosphine relative to rhodium, and then the reaction mixture product is extracted and separated with water (Tokuko Showa). 53-1956
3-j4 and Japanese Patent Application Laid-Open No. 122330/1983). Compared to the distillation separation method 1ζ, the proposed method fζ has advantages such as avoiding thermal decomposition of the product and preventing deterioration of the catalyst components. In order to suppress the elution of rhodium, it is essential to coexist with trisubstituted phosphine in a large excess of 100 to 300 moles relative to rhodium, as described in JP-A-55-68715. . However, in the hydroformylation reaction ζζ of a refinic compound having a terminal vinylidene skeleton such as 3-methyl-5-buten-1-ol, the reaction rate increases when a large excess of trisubstituted phosphine is present with respect to the rhodium complex compound. Therefore, in order to obtain a constant production amount, a reactor with a significantly large capacity is required, which is extremely disadvantageous from an industrial perspective. As shown in Comparative Example 1, which will be described later, this shows that 5-methyl-5-butene-1-5-methyl-5-butene-1-
When the hydroformylation reaction of alcohol was carried out, the conversion rate of 1-methyl-6-buten-1-ol was only 9%.
This is clearly shown by the fact that it was only . From this, in the synthesis reaction of 2-hydroxy-4-methyltetrahydrobilane by hydroformylation ζζ of 3-methyl-6-puten-1-ol, a separation method using water extraction was adopted to separate the product from the reaction mixture. This is considered difficult.

The present inventors focused on the advantage of the water extraction separation method described above in suppressing thermal alteration of rhodium complex compounds and products, and also applied this method in the hydroformylation reaction of 6-methyl-3-buten-1-ol. As a result of intensive studies to adopt this method, we found that, compared to the previously proposed hydroformylation reaction of olefinic compounds using rhodium complex compounds, the reaction was limited to the presence of extremely low concentrations of rhodium complex compounds and low concentrations of trisubstituted phosphine. When the hydroformylation reaction of 5-methyl-3-buten-1-ol is carried out in the reaction solvent of the type described above, the reaction proceeds at an industrially advantageous rate, and the reaction between water or water and polyhydric alcohol is easy. It was discovered that the loss due to the elution of the rhodium complex compound could be maintained at an industrially acceptable level even if the extraction operation was carried out using the mixed solution, and the present invention was completed. That is, the present invention f
According to ζ, aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, or aliphatic hydrocarbons also contain 0.01 to 0.01 in terms of rhodium atoms in a mixed solvent of alicyclic hydrocarbons and aromatic hydrocarbons.
[5-Methyl-5-buten-1-ol was dissolved with hydrogen in the presence of a rhodium complex of 111 degrees (7/e) and a trisubstituted small sphine at a concentration of 0.01 to 10 mmol/e. Hydroformylation is performed using a gas mixture with carbon oxide, 2-hydroxy-4-methyltetrahydropyran is extracted and separated by extracting the reaction mixture with water or a mixed solution of water and polyhydric alcohol, and the raffinate is added to the catalyst solution. As a result, the hydroformylation reaction zone ζζ is circulated, and the reaction proceeds at an industrially satisfactory rate.
The product is separated efficiently, the loss of the rhodium complex compound due to elution into the extraction hydrothorax is kept within an industrially acceptable range, and even when the raffinate is recycled to the hydroformylation reaction zone. Since the catalytic activity is maintained at a substantially satisfactory level, 2-hydroxy-4-methyltetrahydropyran can be produced industrially with advantage.4 In the reaction according to the method of the present invention, alicyclic A common hydrocarbon solvent, an alicyclic hydrocarbon solvent, or a mixed solvent of an aliphatic hydrocarbon or an alicyclic hydrocarbon and an aromatic hydrocarbon is used. Aromatic hydrocarbons have high solubility in rhodium complex compounds and trisubstituted phosphines and are miscible in water.
．． (Since it is a solvent that is preferably used in the hydrolumylation reaction of olefinic compounds that employs a separation method by water extraction), when the olefinic compound is 6-methyl-6-puten-1-ol. This is preferable because the separability of the interface becomes poor during extraction and separation with water.
< , Aromatic hydrocarbons (1) Used in a mixture with aliphatic hydrocarbons or alicyclic hydrocarbons in the reaction according to the method of the present invention5, Mixtures of aliphatic hydrocarbons or alicyclic hydrocarbons and aromatic hydrocarbons The proportion of aromatic hydrocarbons in the solvent is preferably 50% by volume or less, preferably 25% by volume or less.

If the proportion of aromatic hydrocarbons exceeds 50% by volume, interfacial separation properties will deteriorate in the extraction process. Specific examples of aliphatic hydrocarbons and alicyclic hydrocarbons include pentane, hexane, heptane, octane, nonane, decane, cyclo/suthane, cyclooctane, and the like.

Specific examples of aromatic hydrocarbons include IJ1 benzene, toluene, xylene, and the like.

As the Rhodium & ML compound, any rhodium complex compound that has a hydrolumylation catalytic ability and is substantially insoluble or sparingly soluble in water can be used. Many such rhodium complex compounds are known, and a specific example thereof is 1JHh (00) (PP h5)5 (Ph is 7
Ni: Represents a group), 1 for H (C!0) CP (
(:'J14(-J15)5 given EhOe(CO)(L'
Ph5) 2 (represents PI + Huff x = JL/group),
Rhodium acetylacetonate, organic carboxylic acid rhodium 1
7m, Bh4(00), 2.1(h4(co), 6th).
0) (P, Ph5)s, Bh, (CO),.

and I(h6(CO)+6) are excellent in terms of catalytic activity, catalyst solubility, and ease of handling the catalyst.The concentration of the rhodium complex compound in the reaction mixture is 0.01 to 0 in terms of rhodium atoms. .5 milligram atoms/4, preferably within the range of 0.02 to 0.2j gram atoms/l. If the concentration is less than 0.01i:IJ gram atoms/E, the hydrosmall lumylation reaction It is slow and industrially disadvantageous.If the concentration of the rhodium complex compound exceeds 0.5 milligram atom/e, a large amount of the rhodium complex compound will be eluted into the extracted aqueous layer in the extraction process. Surprisingly, despite the high concentration of the rhodium complex compound, the reaction rate tends to decrease, which is not preferable.

The trisubstituted phosphines used in the process of the invention have the general formula 1)B'l(+l1(I[I(i(', R1 and 1
- represents the same or different alkyl group or aryl group.

is a trisubstituted phosphine represented by the following formula (if any one of 1 and 1- is an alkyl group, the remaining two are aryl groups); Specific examples include triphenylphosphine, tritolylnesphine, diphenylpropylphosphine, and the like. The concentration of trisubstituted phosphine in the reaction mixture is selected from within the range of 0.01 to 10 mmol/l. , especially when the concentration of 1ζ trisubstituted phosphine is kept within the range specified in 2 and the trisubstituted phosphine is used in a proportion of 3 to 20 equivalents per gram atom of rhodium in the rhodium complex compound (ζ hydrosmall lumylation reaction rate A favorable result is obtained from the viewpoint of elution loss into the extracted aqueous layer.The trisubstituted sphine is partially eluted into the extracted aqueous layer during extraction. The oxygen contained in Wi-O as a mixed gas pressure impurity is lost due to oxidation, so during long-term use, the concentration in the reaction mixture should be maintained within a constant range. It is desirable to add it periodically or intermittently.

The reaction temperature is desirably selected from a range of 60 to 150°C. When the reaction temperature is less than 60°C, the reaction rate becomes slow, and when the reaction temperature exceeds 150°C, the thermal stability of the rhodium complex compound and the product 2-hydroxy-4-methyltetrahydrobilane decreases. This is a concern, so it is desirable.The reaction pressure is usually 5.
Pressures below 0 atm absolute are used. 63 When the reaction pressure is 3
When the pressure is less than 0 absolute atmospheric pressure, the by-products 3-methyl-2-buten-1-ol and isovaleraldehyde are produced at a high rate, and as a result, the hydroformylation product 2-hydroxy-4 - There is a tendency for the yield of methyltetrahydrobilane to decrease and the stability of the rhodium complex compound to decrease.11 There is no strict upper limit for the reaction pressure, but if the pressure is made unnecessarily high, 2- Since the yield of hydroxy-4-methyltetrahydrobilane does not increase and is undesirable from the viewpoint of equipment costs, operating costs, etc., the reaction pressure is usually preferably not higher than 600 absolute atmospheres.

The ratio of hydrogen as a raw material gas to carbonized carbon is preferably within the range of 5/1 to 1/3 as a molar ratio of the gas entering the reactor. Note that gases that are inert to the hydroformylation reaction, such as methane, ethane, propane, nitrogen,
Helium, argon, carbon dioxide (there is no problem even if any of them coexists in the reaction system.

This hydrolumylation reaction is carried out in a stirred reaction tank or a bubble column reaction tank by a batch method or a continuous method. At this time, the concentration of 2-hydroxy-4-methyltetrahydrofuran in the reaction mixture wave is 0.5 to 5 monoL//a and j (
It is preferable to set the feed rate of 5-methyl-3-buten-1-ol and the residence time of the reaction mixture in the reactor so as to satisfy the following conditions.

The reaction mixture after the hydrolysis reaction is extracted with water or a mixture of water and polyhydric alcohol to extract and separate the product, 2-hydroxy-4-methyltetrahydrobilane. Specific examples of polyhydric alcohols that can be mixed with water include ethylene glycol,
Propylene glycol, 1,4-butanediol, 1,
Examples include 5-bentanediol, 5-methyl-1,5-pentanediol, 1,6-hexanediol, and glycerin. The proportion of polyhydric alcohol in the mixture of water and polyhydric alcohol is 50% by volume or less,
1. It is preferably 30% or less. When the proportion of polyhydric alcohol exceeds 50% by volume, the amount of rhodium complex compounds and trisubstituted sphine eluted into the oil field water layer increases. From an industrial point of view, it is preferable that the ratio of water or a mixture of water and multi-hTs alcohol to the hydroformylation reaction mixture is in the range of 1/3 to 5/1 by volume.

The extraction operation is carried out at a temperature of 0 to 50°C, preferably 10 to 30°C.
It is better to do this with y. This extraction operation is usually carried out under an atmosphere of an inert gas such as nitrogen, helium, or argon, or hydrogen or a hydrogen/carbon mixed gas. As extraction equipment, general-purpose stirring extraction towers (mixer settlers, I (Do, etc.)) and plate-type extraction towers (perforated plate towers, etc.) are generally used.The raffinate layer containing the catalyst component after extraction is recycled to the hydroformylation reaction zone and reused. From the extracted water 1-, unreacted 6-methyl-3-buten-1-ol, II
I product is 6-methyl-2-buten-1=ol,
Isovaleraldehyde, isoamyl alcohol, and 2-hydroxy-4-methyltetrahydrobilane, the main product, can be separated and obtained4.The water and polyhydric alcohol recovered from this operating vessel are recycled to the extraction process.
Can be reused. In addition, rhodium eluted into the extraction water j-side during the extraction operation can be separated and recovered from the residue of the distillation.

2-Hydroxy-4-methyltetrahydrobilane obtained by the method of the present invention can be hydrogenated to produce 3-methyl-1, which is useful as a raw material for polyesters, polyurethanes, etc.
, 5-bentanediol, but also is an important synthetic intermediate for many other useful compounds.

Hereinafter, the present invention will be specifically explained using Examples.

Example 1 A stainless steel autoclave with contents 11 equipped with a thermometer, a magnetic stirrer, a gas inlet, a gas outlet and a pressure holding valve was charged with 0.05 (remol/l) fEh (00) (PP
h5) Charge 51J 0rrL of a hexane solution in which PPh of 5 and 01 mm mono IZl was dissolved, and after thoroughly replacing the system with hydrogen/carbon oxide mixed scum (molar ratio 1/1), reduce the pressure of the autoclave with this mixed gas. 100
The pressure was kept at atmospheric pressure, and the mixture was heated with stirring until the internal temperature reached a constant temperature of 100°C. Afterwards, add JS3- to the metering pump.
Methyl-3-buten-1-]-l 45Q (525 mmol) was continuously fed into the autoclave over a period of 30 minutes. The autoclave is connected to a gas reservoir filled with hydrogen/carbon oxide mixed gas (molar ratio 1/1) through a pressure regulating valve, and the pressure inside the autoclave is always maintained at 100% during the reaction.
Absolute atmospheric pressure was maintained and the gas flow rate from the autoclave was adjusted to be approximately 5 l/h.

When the addition of 6-methyl-3-buten-1-ol was completed, stirring was continued for an additional 2 hours. After a total of 2.5 hours of reaction, the stirring was stopped and the temperature inside the autoclave was cooled to room temperature (after 7 hours, the pressure inside the autoclave was released and a very small amount of the reaction mixture was taken out and analyzed by gas chromatography. The residual line of unreacted 5-methyl-3-buten-1-ol is 26 mmol (iH 195%), and 2
The amount of -hydroxy-4-methyltetrahydrobyran produced was 443 jlJ mol (selectivity 89%). 5 others
- 25 mmol and ! of methyl-2-buten-1-ol and isovaleraldehyde, respectively! 10 mmol was produced.

Next, the reaction mixture in the autoclave was transferred under pressure to a three-necked flask with a capacity of 21 equipped with a stirrer that had previously been purged with nitrogen gas, and 450 ml of water and 50 ml of 1,4-butanediol were added thereto, and nitrogen gas was added thereto. The mixture was stirred in an atmosphere at 30°C for 20 minutes and extracted. When the stirring was stopped, 2HJ was separated by itself. After standing for 15 minutes, both 1-
was separated into liquids. By analyzing the raffinate layer (hexane layer) and extracted water J@, the generated 2-hydroxy-4-
It was found that 96% of methyltetrahydrobilane was extracted into the aqueous extraction layer.

Next, the raffinate residue j- was charged into the autoclave again, and the hydroformylation reaction and extraction of 3-methyl-5-buten-1-ol were carried out under the same conditions and procedure as above. In this way, 5-methyl-5-butene-1-
The hydroformylation reaction and extraction of 5-methyl-6-butene-1 gool were repeated five times in total, and the conversion rate of 5-methyl-6-butene-1 gool was kept within the range of 92-95% each time,
The selectivity of hydroxy-4-methyltetrahydrobilane is constant (J and T).
3 concentrations were analyzed by liquid chromatography, and 1(B
h (CO) (PP h5) The total PPh5i degree in raffle 1, including PPh3 in 5, is always 0.25 to 0.28.
PPh5 as appropriate to be kept within the range of mmol/l.
Added. In addition, the rhodium complex compound eluted into the extracted water layer side was analyzed by atomic absorption spectrometry, and the results showed that the rhodium complex compound eluted into the extracted water layer was only 0.07 to 0.151 aljζ as rhodium metal. Ta.

Example 2 Into the autoclave used in Example 1, 1.0.0125 mmol/l of 1 (114(CO), 2 (rhodium is 0.05 mg/e in terms of atoms) and 0.6 mmol/l of A mixed solution of 10,077 toluene in which P'Ph3 had been dissolved and 400 fluorescein of hexane was charged, and a hydroformylation reaction of 3-methyl-3-buten-1-ol was carried out under the same conditions as in Example 1. Reaction completed. After that, the reaction mixture was analyzed and the conversion rate of 5-methyl-3-buten-1-ol was 94%.
It was found that the selectivity of 2-hydroxy-4-methylte(・lahydropyran) was 90%. Next, 500 g of a mixed solution consisting of 4501 g of water and 50 ml of 3-methyl-1,5-bentanediol was added as an extractant. The extraction operation was carried out in the same manner as in Example 1 except that .

After separation, the raffinate J- and extracted aqueous layer were analyzed to determine the amount of 2-hydroxy-4-methyltetrahydropyran.
It was found that % was extracted. In this way 3
-The hydroformylation reaction and extraction of methyl-6-buten-1-4-l were repeated five times, but 3-methyl-5-
The conversion of buten-1-ol was not substantially reduced. However, in this Example 2, as in Example 1, by analyzing the PPh3 concentration in the raffinate layer,
PPh 5 was added as appropriate so that the total PPh concentration in the raffinate layer was maintained within the range of 0.28 to 0.31 t remol/l. The rhodium complex compound eluted in the extracted aqueous layer contains only 0.05 to f1.1511 as rhodium metal.
It was found that only %l.

Example 3 J-11 was used in Example 1.
, '115) a Oyobi l], 28j' I of J mol/l
'P, dissolve l15, t, dichlorohexane solution 5
0 nJ was charged, the reaction pressure was 120 atm, and the reaction temperature was rt.
The hydroformylation reaction of 3-methyl-3-buten-1-ol was carried out under the same conditions as in Example 1 except that the temperature was 120°C. After the reaction is completed, the reaction mixture is analyzed and the conversion rate of 3-methyl-3-buten-1-ol is 92%, and the selectivity of 2-hydroxy-4-methyltetrahydrobilane is 91%. It was a). Next, an extraction operation was carried out in the same manner as in Example 1 using 400 ml of water, and 400 ml of liquid was added and the extraction operation was repeated. By analyzing the 3 raffinate layer and the extracted aqueous layer, it was found that 84% of the 2-hydroxy-4-methyltetrahydrobilane was extracted.
won. Do it like this - methyl-3-butene-1-
The hydroformylation reaction and extraction of ol were repeated five times, and the conversion of 6-methyl-3-buten-1-ol each time was within the range of 88 to 92%. However, by analyzing the prh3 concentration in the raffinate layer after extraction in the same manner as in Example 1, the total PPb5@J(j
PPh5 was added as appropriate to keep it within the range of 0.38-0.42 mmol/l.

It was found that the rhodium complex compound eluted from the extracted water J-Nakaban ζ was only 0.04 to oaPl as rhodium metal.

Comparative Example 1 1 mmol/l HBh (Co ) in Example 1
(PPh3).

The hydroformylation reaction of 6-methyl-6-buten-1-ol was carried out under the same conditions as in Example 1, except that 2500me of toluene solution containing 50 mmol/l of PPh and 50 mmol/l of PPh was used. After the reaction was completed, analysis of the reaction mixture revealed that the conversion of 3-methyl-3-buten-1-ol was only 9%.

Comparative Example 2 In Example 1, 0.05 Jll Mo JIZi? Same as Example 1 except that a mixed solution consisting of 100 nJ of hexane and 400 ml of toluene in which 25 mmol/l of PI'I] 5 was dissolved was used. The hydroformylation reaction of 3-methyl-6-puten-1-ol was carried out under the following conditions.After the reaction was completed,
Analysis of the reaction mixture showed that the conversion of 3-methyl-6-buten-1--4-ol was only about 8%.

Patent applicant: Kura 1 Co., Ltd. Representative Patent Attorney Ken Honda

Claims (1)

[Claims] 1. 0.01 in terms of rhodium atom in an aliphatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, or a mixed solvent of an aliphatic hydrocarbon or an alicyclic hydrocarbon and an aromatic hydrocarbon. ~0.5
3-Methyl-3-buten-1-ol is reacted with hydrogen and carbon monoxide in the presence of a rhodium complex at a concentration of 'zligram atoms/l and a trisubstituted phosphine at a concentration of 0.01-10 mmol/l. Hydroformylation is performed using a mixed gas, and 2-hydroxy-4-methyltetrahydrobilane is extracted and separated by extracting the reaction mixture with water or a mixed solution of water and polyhydric alcohol, and the raffinate is used as a catalyst solution to rumyl in hydrochloride. 1. A method for producing 2-hydroxy-4-methyltetrahydrobilane, which comprises circulating 2-hydroxy-4-methyltetrahydrobilane into a reaction zone. 2. Hydroformylation reaction at a reaction temperature of 60 to 130°C,
The total pressure is 30 to 30 degrees absolute and the molar ratio of hydrogen to carbon monoxide in the incoming gas is 115 to 3. The method according to claim 1, which is carried out under the conditions of /1. 3. The proportion of aromatic hydrocarbons in the mixed solvent of aliphatic hydrocarbons or alicyclic hydrocarbons and aromatic hydrocarbons is 5.
The method according to claim 1, wherein the amount is 0% by volume or less. 4. The method according to claim 1, wherein the proportion of polyhydric alcohol in the mixed solution of water and polyhydric alcohol is 50% by volume or less.