JPH01121234A - Production of 4-hydroxybutanals - Google Patents

Abstract

PURPOSE:To obtain the title compound which is used as a starting substance of medicines and agrochemicals in high yield under relatively mild conditions without combustible gases such as hydrogen by hydroformylation of allyl alcohol with carbon monoxide and water using a specific catalyst. CONSTITUTION:The hydroformylation of an allyl alcohol or its derivative of formula I (R1-R6 are H, 1-18C aliphatic or aromatic hydrocarbon group) such as allyl alcohol is carried out by allowing the alcohol, preferably in a concentration of 0.001-2mol./l, to react with carbon monoxide and water in a solvent such as tetrahydrofuran in the presence of a catalyst which is composed of rhodium carbonyl cluster Rh6(CO)16 and a trialkylphosphine such as tributyl phosphine, preferably at 30-150 deg.C under 0.2-50kg/cm<2> CO partial pressure to give the subject compound of formula II with high selectivity of straight-chain products such as 4-hydroxybutanal which is used in the formation of 1,4-butanediol, a starting substance of polyester or polyurethane.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing 4-hydroxybutanals,
More specifically, the present invention relates to a method for producing the corresponding 4-hydroxybutanal or its derivative from allyl alcohol or its derivative. 4-Hydroxybutanals obtained by the method of the present invention are not only useful compounds themselves as raw materials for medicines and agricultural chemicals, but also are industrially important 1. It can be easily converted into 4-butanediols.

[Conventional technology]

Conventionally, allyl alcohol is treated in the presence of a transition metal compound,
-It is known to obtain 4-hydroxybutanal by reacting carbon oxide with hydrogen (US Pat. No. 4,064,145)
. However, in this method, not only a linear aldehyde compound but also 1-hydroxy-2-methylpropionaldehyde is produced as a by-product, and it cannot be said that sufficient selectivity is obtained. Furthermore, since this method uses highly flammable hydrogen as a raw material, there is a safety problem.Therefore, there is a need for a method that is industrially safe and capable of producing the desired product at a lower cost.

Bull, Cheffl, Soc, Jap,...
54.249 (1981) describes an example in which a hydroformylation reaction occurs by reacting propylene with carbon monoxide and water in the presence of a catalyst consisting of octacarbonyl dicobalt to give the corresponding aldehyde. , severe reaction conditions (Co pressure crab 100kg/c+(,
In addition, the selectivity for linear aldehydes is not sufficient.

It is also well known to perform hydroformylation of olefins under water gas conversion reaction conditions. For example, Chew,
Lett, 1465 (1984), using hexarodium hexadecacarbonyl as a catalyst, N,N
, N',N'-tetramethyl-1,3-propanediamine as a solvent, an example is described in which allyl alcohol is reacted with carbon monoxide and water to produce 1,4-butanediol. However, in this case, the aldehyde produced is reduced to an oxo alcohol, and it is difficult to obtain the product as an aldehyde.

In addition, Japanese Patent Publication No. 41-6284 discloses examples of hydroformylation by reacting allyl alcohol with carbon oxide and hydrogen using a rhodium complex compound modified with trisubstituted phosphine. generally known. In this case, the selectivity for linear aldehydes is considerably improved, but as mentioned above there is the disadvantage that hydrogen must be used.

[Problem that the invention seeks to solve]

Generally, using a phosphine-coordinated rhodium catalyst,
The hydroformylation reaction of allyl alcohol allows the product to be obtained under relatively mild conditions, but it requires the use of hydrogen gas, compared to when using a stable compound such as water. , the risk increases. Furthermore, although the linear chain ratio is considerably improved compared to a system that does not use phosphine, it cannot be said to be sufficient.

An object of the present invention is to produce the corresponding 4-hydroxybutanal or its derivative in good yield by reacting allyl alcohol or its derivative with carbon monoxide without using flammable gas such as hydrogen. It is in.

[Means for solving problems]

Therefore, as a result of repeated studies to overcome these drawbacks, the present inventors discovered that the Rh catalyst can be used under limited conditions without using a flammable gas such as hydrogen that has a high risk of ignition. It has been found that the hydroformylation reaction of allyl alcohol or its derivatives can be carried out using CO and water, and that in this case the selectivity for the linear product is very high, and the present invention has been made based on the present invention. It has been completed.

According to the invention, namely general formula I, ORIR,R.

II l l 1 H-C-C-C-C-OH... 12HR5 [In the above formula, R1, R2, R3, R4 and R5 are each independently a hydrogen atom or C, ~18 aliphatic or Representing an aromatic hydrocarbon group] A method for producing 4-hydroxybutanal or a derivative thereof is provided, the method comprising:
General formula ■, R, R3R.

\ 11 C=C-C-OH... ■ / I R2R5 [In the above formula, R1, R2, R3, R4 and R5 represent the same thing as defined above] Allyl alcohol or its A process characterized in that the derivative is hydroformylated with carbon oxide and water in the presence of a catalyst consisting of a rhodium carbonyl cluster and a trialkylphosphine.

The rhodium carbonyl cluster used here consists of three or more metal atoms containing rhodium as the central metal, and the metal-
It is a rhodium cluster complex that has a direct metal bond and contains carbonyl as a ligand. The rhodium carbonyl cluster may contain a different metal such as cobalt or iridium as long as such conditions are satisfied. Such compounds include Rh6 (Co)l
s, Rh4 (Co) 12, Rha Co (Co)
12, etc., but considering stability and economic efficiency, Rha (Co) 1s, Rh, (Go)
12 is preferred, and among them, Rh6(Co)u+ is particularly preferred. Of course, these compounds may be prepared in advance and charged into the reaction system, or may be directly produced in the reaction system.

Another important factor here is the coexistence of trialkylphosphines with these rhodium cluster complexes. If trialkylphosphine is not present, the reaction will not occur at all, or even if the reaction occurs, the product will not stop at the aldehyde and will be further hydrogenated to become an oxo alcohol. , there are many other by-products, making the system complex.

The more basic the trialkylphosphine used is, the higher the reactivity is, so it is desirable that the alkyl group contains an aliphatic alkyl group. These include trimethylphosphine, triethylphosphine, tri-n-propylphosphine, tri-n-butylphosphine, tri-S
-butylphosphine, tri-1so-butylphosphine, tri-t-butylphosphine, tri-n-octylphosphine, etc., and tri-n-butylphosphine is particularly preferred from the viewpoint of stability, reactivity, and economy in the presence of water. There is an optimum amount for the presence, since if it is too small, the selectivity will be poor, and if it is too large, the reaction rate will be low. It is necessary to use at least an equimolar amount with respect to the rhodium metal atom, and it is preferable to use an excess amount of 4 times or more by mole or more, but it is preferable not to exceed 100 times by mole.

Allyl alcohol or its derivative as a starting material is represented by the general formula (2) above. In terms of reaction rate, it is better to have fewer substituents on the carbon atom of the double bond. Examples of such substituents include allyl alcohol, 1-buten-3-ol, 3-methyl-1-butene-
Examples include 3-ol, 1-phenyl-2-propen-1-ol, and the like.

The reaction solvent must be compatible with water, must be capable of dissolving at least the rhodium carbonyl cluster, trialkylphosphine, and allyl alcohol or its derivative, and must be capable of providing an appropriate reaction rate. Preferred examples of such compounds include pyridine derivatives, cyclic ether compounds, aliphatic ether compounds containing hydroxyl groups, and aliphatic saturated alcohols. Specific examples include pyridine, α-picoline, γ-picoline,
Mention may be made of tetrahydrofuran, dioxane, 2-ethoxyethanol and ethanol, with pyridine, T-picoline and tetrahydrofuran being particularly preferred.

Regarding the reaction conditions, if the partial pressure is too low or too high, the reaction rate will be slow. Specifically, 0.2
~50 kg/CIA, particularly preferably 1-30 kg/CIA
It is preferable to select from the range of -.

If the concentration of allyl alcohol or its derivative is too low, the reaction rate will be extremely slow, and if it is too high, the trialkylphosphine will not dissolve, so it is necessary to select it from an appropriate concentration range.

Although it varies depending on the solvent used, in order to complete the reaction in several hours, preferably 0.001 to 2 mol/Il,
More preferably 0.05 to 1 mol/7! It is good to be.

The amount of rhodium carbonyl cluster used is preferably 1/10 to 1/10,000 mol, more preferably 1/1/10,000 mol of allyl alcohol or its derivative in terms of rhodium atoms.
It is 10 to 1/1000 mole. As mentioned above, the trialkylphosphine needs to be used in excess of rhodium, preferably 1 to 100 times the molar amount, more preferably 4 to 10 times the molar amount in terms of rhodium atoms of the rhodium carbonyl cluster.

If the amount of water used is too small, the reaction itself will not proceed, and if too much water is used, the trialkylphosphine will not dissolve and a heterogeneous reaction system will result, which is not preferable. Although this also varies depending on the solvent used, it is generally 1 to 100 times the mole of allyl alcohol or its derivative, preferably 1
It is preferable to use 0 to 20 times the molar amount.

The reaction temperature is preferably in the range of 30 to 150°C, more preferably 40 to 120°C, since the reaction rate is slow at low temperatures, and the 4-hydroxybutanal or its derivatives produced becomes unstable at too high temperatures. It's good to have one.

As mentioned above, the characteristics of this reaction are that 4-hydroxybutanal or its derivatives can be obtained from allyl alcohol derivatives in a relatively high yield using water and CO, and n-/is .

- The reason is that the ratio is high, and when other by-products are analyzed, 1.
They were 4-butanediols, γ-butyrolactones, etc., and the selectivity of linear chains in the hydroformylation reaction was almost 100%.

〔Example〕

The present invention will be further explained below with reference to Examples.

Example 1 53.4 mg (0.05 m
mo ]) and tributylphosphine 3.03 g (
15 mmol), water 0.865 g (48 mmol
I), allyl alcohol 0.174 g (3 mmo
l) and 1.0 mA of THF (tetrahydrofuran) as a solvent.

After the reaction vessel was sufficiently replaced with carbon monoxide, a positive CO pressure of 5 kg/c+fl was applied, and the internal temperature was raised to 80° C. while stirring, and maintained at that temperature. Since the internal pressure decreases as the reaction progresses, carbon monoxide was added to maintain it at 5 kg/cJ, and the reaction was carried out under these conditions for 3 hours.

After the reaction was completed, the reaction solution was analyzed by gas chromatography, and it was found that all the raw material allyl alcohol had been consumed. Analysis using diphenyl as the inner product revealed that 4-hydroxybutanal was 2.3 mmol (yield 77%).
0.43 mmol of 1.4-butanediol (yield 14
%), T-butyrolactone is 0.063 mmol 1
(yield 2%).

Example 2 In a glass pressure-resistant reactor with an internal volume of 50 m1, R was added as a catalyst.
hs (Co) 1853.3 mg (0.05 mmo I
) and tributylphosphine 0.303 g (1.5 mm
o 1), water 0.863 g (48 mmo 1),
Allyl alcohol 0.174g (3mmol),
and 8 mft of pyridine as a solvent.

After thoroughly purging the reaction vessel with carbon monoxide, a positive CO pressure5. kg/cm! While stirring, the internal temperature was raised to 80°C and maintained at that temperature. The internal pressure decreases as the reaction progresses, so keep it at 5 kg/cn.
The reaction was continued under these conditions for 4 hours while adding carbon oxide.

After the reaction was completed, the reaction solution was analyzed by gas chromatography, and it was found that all the raw material allyl alcohol had been consumed. Analysis using diphenyl as the inner product revealed that 4-hydroxybutanal was 1.9 mmol (yield 63%).
1.4-butanediol is 0.80 mmol (yield 27
%), γ-butyrolactone 0.14 mmol (yield 5
%) was generated.

Example 3 53.4 mg (0.05 mmo
l) and tributylphosphine 3.03 g (15 m
mol), water 0.862 g (48 mmol I)
, l-buten-3-ol 0.385 g (6 mmo
l) ), and pyridine 8m7 as solvent! I prepared it.

After the reaction vessel was sufficiently purged with carbon monoxide, a positive CO pressure of 5 kg/cn was applied, and the internal temperature was raised to 80° C. while stirring, and maintained at that temperature. Since the internal pressure decreases as the reaction progresses, carbon monoxide was added to keep it at 5 kg/cm, and the reaction was carried out under these conditions for 5 hours.

After the reaction was completed, the reaction solution was analyzed by gas chromatography, and it was found that all of the raw material 1-buten-3-ol was consumed. When analyzed using diphenyl in the inner product,
4.2 mmol of 4-hydroxypentanal (yield 7
0%), 1.2 mmol of 1.4-bentanediol
(yield: 20%), and 0.18 mmol (yield: 2%) of 2-methyl-γ-butyrolactone were produced.

Comparative Example 1 The same procedure as in Example 2 was carried out except that water was not added. When analyzed by gas chromatography,
Only 21% of the raw material allyl alcohol was reacted, and the identified product was 0.006 gamma-butyrolactone.
mmol (yield 2%), propionaldehyde 0.90
It was only mmo + (yield 30%).

Comparative Example 2 The same procedure as in Example 2 was carried out except that tributylphosphine was not added. Analysis by gas chromatography revealed that all the raw material allyl alcohol had been consumed. However, the identified products were γ-butyrolactone 0.35 mmol (yield 12%), propionaldehyde 0.76 mmol (yield 26%), n-propatol 0.17 mmol (yield 6%), 4-hydroxy The amount of butanal was only 0.50 mmol (yield 17%).

〔Effect of the invention〕

According to the present invention, allyl alcohol or a derivative thereof is reacted with carbon monoxide under relatively mild conditions without using a flammable gas such as hydrogen to produce the corresponding 4-hydroxybutanal in good yield. or its derivatives.

Claims (1)

[Claims] 1. General formula I, ▲There are mathematical formulas, chemical formulas, tables, etc.▼... I [In the above formula, R_1, R_2, R_3, R_4 and R_
5 is each independently a hydrogen atom or C_1_ to_1_8
represents an aliphatic or aromatic hydrocarbon group] In producing 4-hydroxybutanal or its derivatives, there are general formulas II, ▲numeric formulas, chemical formulas, tables, etc.▼...II [In the above formula, R_1 , R_2, R_3, R_4 and R_
5 represents the same thing as defined above] Allyl alcohol or its derivative represented by is hydroformylated with carbon monoxide and water in the presence of a catalyst consisting of a rhodium carbonyl cluster and a trialkylphosphine. Method.