JPH06336456A - Production of 2-formyl-4-acyloxy-1-butene - Google Patents

Abstract

PURPOSE:To obtain the subject compound useful as a raw material for vitamin A, etc., in high yield by reacting an allyl carboxylate with hydrogen and carbon monoxide in the presence of a rhodium catalyst and subsequently reacting with formaldehyde. CONSTITUTION:An allyl carboxylate of the formula CH2=CH-CH2-O-CO-R (R is lower alkyl) is subjected to hydroformylation with hydrogen and carbon monoxide in the presence of rhodium catalyst at 40-150 deg.C under the pressure of 1-100atm to obtain 3-formylpropyl carboxylate of the formula O=CH-CH2- CH2-CH2-O-CO-R. The reactional product is further subjected to methylenation in the presence of formaldehyde and a secondary amine (e.g. dimethylamine acetic acid salt) at 80-200 deg.C, thus the objective product of the formula is obtained. This process enables to obtain the objective product from the starting material of a low cost allyl carboxylate under relatively mild reaction conditions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing 2-formyl-4-acyloxy-1-butene useful as a raw material for producing vitamin A.

[0002]

2. Description of the Related Art 2-Formyl-4-acyloxy-1-
As a method for producing butene from a relatively inexpensive raw material in an industrially advantageous process, 1,4-diacyloxy-2-butene is subjected to a hydroformylation reaction, and the resulting hydroformylation reaction product is thermally decomposed. A method has been proposed (see JP-A-51-146413).

[0003]

However, 1,4-diacyloxy-2-butene used as a starting material in the above production method still has a problem that it is relatively expensive. Moreover, since the 1,4-diacyloxy-2-butene is less susceptible to the hydroformylation reaction because it has an internal olefin structure, a high pressure of 100 atm or more is required in order to achieve a practical reaction rate in the reaction. It is necessary to adopt. In such a high-pressure reaction, not only a special reaction device is required, but also great consideration is required in terms of safety. From these points, in reality, no industrially suitable production method of 2-formyl-4-acyloxy-1-butene has been proposed yet.

[0004]

Means for Solving the Problems The present inventors have conducted extensive studies to find a method for producing 2-formyl-4-acyloxy-1-butene under low cost and relatively mild conditions, and as a result, propylene The present invention has been completed by paying attention to the use of allylcarboxylate, which is produced in a large amount and at low cost by an acyloxylation reaction, as a starting material. That is, the present invention provides the following general formula (I)

[0005]

[Chemical 4]

By reacting an allylcarboxylate represented by the formula (wherein R represents a lower alkyl group) with hydrogen and carbon monoxide in the presence of a rhodium catalyst,
The following general formula (II)

[0007]

[Chemical 5]

(In the formula, R is as defined above.)
The following general formula (III) is characterized in that 3-formylpropylcarboxylate represented by the formula (3) is obtained, and then the 3-formylpropylcarboxylate is reacted with formaldehyde in the presence of a secondary amine salt.

[0009]

[Chemical 6]

(In the formula, R is as defined above.)
Is a process for producing 2-formyl-4-acyloxy-1-butene.

The above general formulas (I), (II) and (II)
Specific examples of the lower alkyl group represented by R in I) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group and a hexyl group.

The hydroformylation reaction of allylcarboxylate which is the first step reaction in the production method of the present invention is carried out by reacting allylcarboxylate with hydrogen and carbon monoxide in the presence of a rhodium catalyst. The rhodium catalyst in the hydroformylation reaction is
Usually, it is used in an amount in the range of 0.1 to 10 milligram atom in terms of rhodium atom per liter of liquid phase in the hydroformylation reaction. As the rhodium catalyst, a rhodium complex catalyst having a trivalent organic phosphorus compound as a ligand is desirable, and a rhodium carbonyl complex catalyst having a trivalent organic phosphorus compound as a ligand is particularly preferable.

The rhodium complex catalyst having a trivalent organic phosphorus compound as a ligand can be formed in the reaction system by introducing the rhodium compound and the trivalent organic phosphorus compound into the reaction system. It is also possible to prepare the compound outside the hydroformylation reaction system by mixing the compound and a trivalent organic phosphorus compound in a solution and introducing carbon monoxide into the mixture.

Many such rhodium compounds are known, for example, HRh (CO) (PA ↓ 3) ↓ 3 (wherein A
Represents an aryl group or an aryloxy group. same as below. ), Rh ↓ 4 (CO) ↓ 12, Rh ↓ 6 (CO) ↓ 16,
Rh (acac) (CO) ↓ 2 (in the formula, acac represents an acetylacetonato group. The same applies hereinafter), [Rh (C
O) ↓ 2 (PA ↓ 3) ↓ 2] ↓ 2, RhCl ↓ 3 ・ 3H ↓ 2O,
Rh ↓ 2O ↓ 3 and so on.

The group A in the trivalent organophosphorus compound PA ↓ 3 that the rhodium catalyst or its precursor rhodium compound has as a ligand includes a phenyl group, a p-chlorophenyl group, a p-methoxyphenyl group and a -C group. ↓ 6H ↓ 4
-M-SO ↓ 3M (M is Li, Na or K.)
And the like; or an aryloxy group such as a 2-t-butylphenoxy group, a 2,4-di-t-butylphenoxy group, and a 2-isopropylphenoxy group.
The three A's in PA ↓ 3 may be the same or different from each other.

It is desirable that these phosphorus compounds be present in an excess amount with respect to the rhodium atom in the hydroformylation reaction system, and usually 3 g per 1 g atom of rhodium.
˜200 mol, especially 30 to 150 mol is preferred.

In the present invention, the bidentate phosphine is present in an amount of 0.25 to 2 mol per gram atom of rhodium together with the trivalent organic phosphorus compound represented by PA ↓ 3 above. It is preferable because the catalyst activity can be maintained for a long period of time. Specific examples of the bidentate phosphine include 1,3-diphenylphosphinopropane, 1,4
-Diphenylphosphinobutane and the like can be mentioned.

The hydroformylation reaction in the present invention comprises
It is carried out in the presence or absence of a solvent inert to the reaction. Specific examples of the solvent that can be used include hydrocarbons such as hexane, benzene and toluene; alcohols such as methanol and butanol; ethers such as dibutyl ether and dioxane; esters such as methyl acetate and octyl phthalate; acetonitrile. Sulfolane; ethylene carbonate and the like. The amount of the solvent used is not particularly limited, but it is usually 20 to 80% by weight based on the allyl carboxylate.

The hydroformylation reaction is carried out at 40 to 150 ° C.
At a temperature of 70 to 130 ° C., preferably 70 to 130 ° C. The hydrogen and carbon monoxide used in the reaction are usually in the range of 1: 2 to 5: 1 in terms of molar ratio of hydrogen to carbon monoxide charged into the reaction system. Since the hydroformylation reaction in the present invention proceeds even at a relatively low pressure, 100
It is not necessary to employ pressures above atmospheric pressure. For this reason, the reaction pressure is generally in the range of 1 to 100 atm, preferably in the range of 2 to 60 atm. The reaction time depends on the reaction temperature,
Although it can be appropriately selected depending on the reaction pressure and the like, it is usually 1 to 10 hours. The hydroformylation reaction can be carried out in a batch system or a continuous system, but it is industrially advantageous to employ a continuous system in which raw materials are continuously fed.

Separation of the catalyst component from the reaction mixture obtained by the hydroformylation reaction is carried out by subjecting the reaction mixture to distillation or extraction operation. The separated catalyst component can be reused in the hydroformylation reaction.

3-obtained by hydroformylation reaction
Formylpropylcarboxylate is then converted to 2-formyl-4-acyloxy-1-butene by reacting with formaldehyde in the presence of a secondary amine salt. The 3-formylpropylcarboxylate obtained by the hydroformylation reaction is preferably separated from the reaction mixture obtained by the reaction by distillation, but can be reacted with formaldehyde without being separated from the reaction mixture. As the formaldehyde used here, an aqueous formaldehyde solution having a concentration of 10 to 60% by weight or more is desirable because it is easy to handle and inexpensive. The amount of formaldehyde used is usually 3-
For every mole of formylpropylcarboxylate, 0.
It is 7 to 1.5 mol, preferably 0.9 to 1.1 mol.

The secondary amine salt used as a catalyst in the methyleneation reaction using formaldehyde in the present invention is a salt of an aliphatic carboxylic acid having a carbon number of 2 to 18 with a secondary amine or hydrochloric acid, boric acid, Salts of inorganic acids such as carbonic acid are preferred. Preferred secondary amines are aliphatic secondary amines such as dimethylamine, dibutylamine, dioctylamine, didecylamine and the like. Further, specific examples of the aliphatic carboxylic acid having 2 to 18 carbon atoms include acetic acid,
Examples thereof include propionic acid, butyric acid, caprylic acid, 2-ethylhexanoic acid, stearic acid and the like. The secondary amine salt is
It is usually used in an amount of 1 to 20% by weight based on the liquid phase in the reaction system.

The methyleneation reaction is usually carried out at a temperature of 80 to 200 ° C, preferably 100 to 170 ° C,
The reaction time can be appropriately selected depending on the reaction temperature and the like, but is usually 0.1 to 60 minutes. In the methyleneation reaction, if the reaction is continued unnecessarily, by-products will increase, so it is desirable to take out the reaction mixture liquid from the reaction system promptly after the completion of the reaction.

The desired product, 2-formyl-4-acyloxy-1-butene, can be separated and purified from the methyleneation reaction mixture by distillation.

[0025]

EXAMPLES The present invention will be specifically described below with reference to examples. The present invention is not limited to these examples.

Example 1 In a magnetic stirring type autoclave having an internal volume of 100 ml, 15 ml of toluene and 40.1 g (0.40 g of allyl acetate) were added.
mol), hydridocarbonyl-tris (triphenylphosphine) rhodium (I) 152 mg (0.17 mm)
ol), 1.97 g of triphenylphosphine (7.5 m)
mol) and 1,4-diphenylphosphinobutane 6
4.4 mg (0.15 mmol) was charged, and the atmosphere in the reaction system was sufficiently replaced with a mixed gas of hydrogen and carbon monoxide. The reaction system was pressurized to 10 atm with a mixed gas having a hydrogen / carbon monoxide molar ratio of 3/1, and then reacted at 120 ° C. for 3 hours with vigorous stirring. During the reaction, a mixed gas having a hydrogen / carbon monoxide molar ratio of 3/1 was supplied to the autoclave at a rate of 5 liters / hour, and part of the gas in the autoclave was discharged to reduce the pressure in the reaction system to 10 Maintained at atmospheric pressure. After the reaction is completed, gas is released,
After cooling, the reaction mixture was taken out. Toluene was distilled off from the reaction mixture with an evaporator, and the remaining mixture was distilled under reduced pressure to obtain 34.1 g of 3-formylpropyl acetate. The reaction rate based on the charged allyl acetate is 98.
%, The selectivity was 67%.

26.0 g (0.20 mol) of the obtained 3-formylpropyl acetate and 13.3 g of a 45% by weight aqueous formaldehyde solution (formaldehyde 0.20 m
ol) and 1.05 g of dimethylamine acetate,
By feeding into a reaction tube immersed in a 0 ° C bath, 1
The reaction was carried out at a temperature of 60 ° C. for a contact time of 30 seconds, and the reaction mixture flowing out of the reaction tube was immediately introduced into a cooled trap and cooled. After completion of the feed, the reaction mixture collected in the trap was distilled under reduced pressure to obtain 26.7 g of 2-formyl-4-acetoxy-1-butene as a fraction having a boiling point of 68 to 73 ° C./5 mmHg. The reaction rate based on the charged 3-formylpropyl acetate was 98%, and the selectivity was 96%.

Example 2 In a magnetic stirring type autoclave having an internal volume of 100 ml, 25 ml of toluene and 23.6 g (0.24 g of allyl acetate) were added.
mol), rhodium (I) dicarbonylacetylacetonate 3.9 mg (0.015 mmol) and tris (2,4-di-t-butylphenyl) phosphite 1
9.4 mg (0.30 mmol) was charged, and the atmosphere in the reaction system was sufficiently replaced with a mixed gas of hydrogen and carbon monoxide. After the reaction system was pressurized to 60 atm with a mixed gas having a hydrogen / carbon monoxide molar ratio of 1/1, the reaction was carried out at 120 ° C. for 5 hours with vigorous stirring. During the reaction, a mixed gas having a hydrogen / carbon monoxide molar ratio of 1/1 was supplied to the autoclave at a rate of 5 liters / hour, and part of the gas in the autoclave was discharged to reduce the pressure in the reaction system to 60%. Maintained at atmospheric pressure. After the reaction is completed, gas is released,
After cooling, the reaction mixture was taken out. Toluene was distilled off from the reaction mixture with an evaporator, and the remaining mixture was distilled under reduced pressure to obtain 14.8 g of 3-formylpropyl acetate. The reaction rate based on the charged allyl acetate is 95.
%, The selectivity was 66%.

26.0 g (0.20 mol) of the obtained 3-formylpropyl acetate and 16.2 g of a 37% by weight aqueous formaldehyde solution (formaldehyde 0.20 m
ol) and 1.89 g of dimethylamine acetate 170
By feeding into a reaction tube immersed in a bath at ℃ 16
The reaction was carried out at a temperature of 0 ° C. for a contact time of 30 seconds, and the reaction mixture flowing out of the reaction tube was immediately introduced into a cooled trap and cooled. After completion of the feed, the reaction mixture collected in the trap is distilled under reduced pressure to give 2-formyl-4-acetoxy-1-butene 2 as a fraction having a boiling point of 68 to 73 ° C./5 mmHg.
6.4 g was obtained. The reaction rate based on the charged 3-formylpropyl acetate was 99%, and the selectivity was 94%.

[0030]

INDUSTRIAL APPLICABILITY According to the present invention, inexpensive allylcarboxylate can be used as a starting material to produce 2-formyl-4-acyloxy-1-butene under relatively mild conditions in good yield. it can. Therefore, according to the present invention, 2-
An industrially advantageous method for producing formyl-4-acyloxy-1-butene is provided.

Claims (1)

[Claims] 1. The following general formula (I): (Wherein R represents a lower alkyl group) is reacted with hydrogen and carbon monoxide in the presence of a rhodium catalyst to give a compound represented by the following general formula (II): (In the formula, R is as defined above.) 3
-Formylpropylcarboxylate is obtained, then the 3
-Formyl propyl carboxylate is reacted with formaldehyde in the presence of a secondary amine salt, having the following general formula (III): (In the formula, R is as defined above.) 2
-Method for producing formyl-4-acyloxy-1-butene.