JP3228485B2 - Method for producing 2-formyl-4-acyloxy-1-butene - Google Patents

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-
A method for producing butene from a relatively inexpensive raw material in an industrially advantageous process comprises hydroformylating 1,4-diacyloxy-2-butene and thermally decomposing the resulting hydroformylation reaction product. 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 still relatively expensive. In addition, since the 1,4-diacyloxy-2-butene has an internal olefin structure, it is difficult to undergo a hydroformylation reaction. Therefore, in order to achieve a practical reaction rate in the reaction, a high pressure of 100 atm or more is required. It is necessary to adopt. Such a high-pressure reaction requires not only a special reaction apparatus but also a great deal of safety. In view of these points, an industrially suitable production method of 2-formyl-4-acyloxy-1-butene has not been proposed yet.

[0004]

Means for Solving the Problems The present inventors have repeatedly studied to find a method for producing 2-formyl-4-acyloxy-1-butene at low cost and under relatively mild conditions. The present invention has been completed by focusing on using, as a starting material, allyl carboxylate which is produced in large quantities and at low cost by an acyloxylation reaction. That is, the present invention relates to the following general formula (I)

[0005]

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By reacting allyl carboxylate 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]

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(Wherein R is as defined above)
Wherein the 3-formylpropyl carboxylate is reacted with formaldehyde in the presence of a secondary amine salt.

[0009]

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(Wherein, R is as defined above.)
Is a method for producing 2-formyl-4-acyloxy-1-butene represented by the formula:

The above general formulas (I), (II) and (II)
In I), specific examples of the lower alkyl group represented by R 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 of allyl carboxylate, which is the first step in the production method of the present invention, is carried out by reacting allyl carboxylate 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 atoms in terms of rhodium atom per liter of liquid phase in the hydroformylation reaction. The rhodium catalyst is preferably a rhodium complex catalyst having a trivalent organic phosphorus compound as a ligand, and particularly preferably a rhodium carbonyl complex catalyst having a trivalent organic phosphorus compound as a ligand.

A 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. The compound can be prepared outside the hydroformylation reaction system by mixing the compound and the trivalent organic phosphorus compound in a solution and introducing carbon monoxide into the solution.

Many such rhodium compounds are known, for example, HRh (CO) (PA ↓ 3) ↓ 3 (where A is
Represents an aryl group or an aryloxy group. same as below. ), Rh ↓ 4 (CO) ↓ 12, Rh ↓ 6 (CO) ↓ 16,
Rh (acac) (CO) ↓ 2 (acac represents an acetylacetonate group; the same applies hereinafter), [Rh (C
O) ↓ 2 (PA ↓ 3) ↓ 2] ↓ 2, RhCl ↓ 3.3H
Rh ↓ 2O ↓ 3 and the like.

The group A in the trivalent organic phosphorus compound PA ↓ 3 possessed by the rhodium catalyst or the precursor thereof as a ligand is phenyl, p-chlorophenyl, p-methoxyphenyl, -C ↓ 6H ↓ 4
-M-SO ↓ 3M (M is Li, Na or K.)
And 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.

These phosphorus compounds are desirably present in an excess amount relative to rhodium atoms in the hydroformylation reaction system.
It is preferably present in an amount of from 200 to 200 mol, particularly preferably from 30 to 150 mol.

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. It is preferable because the catalyst activity can be maintained for a long time. Specific examples of bidentate phosphines include 1,3-diphenylphosphinopropane, 1,4
-Diphenylphosphinobutane and the like.

The hydroformylation reaction in the present invention comprises
The reaction 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 can be generally used at 20 to 80% by weight based on the allyl carboxylate.

The hydroformylation reaction is carried out at 40 to 150 ° C.
, Preferably at a temperature of 70 to 130 ° C. 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 to be 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 according to the reaction pressure and the like, it is usually 1 to 10 hours. Although the hydroformylation reaction can be carried out in a batch mode or a continuous mode, it is industrially advantageous to employ a continuous mode in which the raw materials are continuously fed.

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

3- obtained by the hydroformylation reaction
Formylpropyl carboxylate 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 desirably 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 solution of formaldehyde having a concentration of 10 to 60% by weight is preferable because it is easy to handle and inexpensive. The amount of formaldehyde used is usually 0.7 to 0.7 mol per 1 mol of 3-formylpropylcarboxylate.
1.5 mol, preferably 0.9 to 1.1 mol.

The secondary amine salt used as a catalyst in the methylene reaction using formaldehyde in the present invention includes a secondary amine salt of an aliphatic carboxylic acid having 2 to 18 carbon atoms, hydrochloric acid, boric acid, Salts of inorganic acids such as carbonic acid are preferred. As the secondary amine, an aliphatic secondary amine such as dimethylamine, dibutylamine, dioctylamine, and didecylamine is preferable. 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, and stearic acid. Secondary amine salts are
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 at a temperature of 100 to 170 ° C.
The reaction time can be appropriately selected according to the reaction temperature and the like, and is usually 0.1 to 60 minutes. In the methylene reaction, if the reaction is continued unnecessarily, by-products increase. Therefore, it is desirable that the reaction mixture be immediately taken out of the reaction system after the reaction.

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

[0025]

The present invention will be specifically described below with reference to examples. Note that the present invention is not limited by these examples.

Example 1 In a magnetic stirring autoclave having an internal volume of 100 ml, toluene 15 ml and allyl acetate 40.1 g (0.40 g) were added.
mol), 152 mg (0.17 mm) of hydridecarbonyl-tris (triphenylphosphine) rhodium (I).
ol), 1.97 g (7.5 m) of triphenylphosphine
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. After the reaction system was pressurized to 10 atm with a mixed gas having a hydrogen / carbon monoxide molar ratio of 3/1, the reaction was carried out 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 liter / hour, and a part of the gas in the autoclave was discharged. Atmospheric pressure was maintained. After the reaction is completed, release gas,
Upon cooling, the reaction mixture was removed. 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. Reaction rate based on charged allyl acetate is 98
% And selectivity was 67%.

26.0 g (0.20 mol) of the obtained 3-formylpropyl acetate, 13.3 g of a 45% by weight aqueous solution of formaldehyde (0.20 m of formaldehyde)
ol) and 1.05 g of dimethylamine acetate were added to 17
By feeding to a reaction tube immersed in a bath at 0 ° C, 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 the feed was completed, 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 conversion based on the charged 3-formylpropyl acetate was 98%, and the selectivity was 96%.

Example 2 In a magnetic stirring autoclave having an internal volume of 100 ml, toluene 25 ml and allyl acetate 23.6 g (0.24 g) were added.
mol), 3.9 mg (0.015 mmol) of rhodium (I) dicarbonylacetylacetonate 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 a part of the gas in the autoclave was discharged. Atmospheric pressure was maintained. After the reaction is completed, release gas,
Upon cooling, the reaction mixture was removed. 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. Reaction rate based on charged allyl acetate is 95
%, Selectivity was 66%.

26.0 g (0.20 mol) of the obtained 3-formylpropyl acetate, 16.2 g of a 37% by weight aqueous solution of formaldehyde (0.20 m of formaldehyde)
ol) and 1.89 g of dimethylamine acetate 170
By feeding the reaction tube immersed in a bath at
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 the feed was completed, the reaction mixture collected in the trap was distilled under reduced pressure to obtain 2-formyl-4-acetoxy-1-butene 2 as a fraction having a boiling point of 68 to 73 ° C / 5 mmHg.
6.4 g were obtained. The conversion based on the charged 3-formylpropyl acetate was 99%, and the selectivity was 94%.

[0030]

According to the present invention, 2-formyl-4-acyloxy-1-butene can be produced in good yield under relatively mild conditions using inexpensive allyl carboxylate as a starting material. it can. Therefore, according to the present invention, 2-
An industrially advantageous process for the production of formyl-4-acyloxy-1-butene is provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C07B 61/00 300 C07B 61/00 300

Claims (1)

(57) [Claims] 1. A compound represented by the following general formula (I) (Wherein R represents a lower alkyl group) by reacting allyl carboxylate represented by the following general formula (II) with hydrogen and carbon monoxide in the presence of a rhodium catalyst. (Wherein R is as defined above)
-Formylpropyl carboxylate is obtained,
-Reacting formylpropyl carboxylate with formaldehyde in the presence of a secondary amine salt, characterized by the following general formula (III): (Wherein R is as defined above)
A method for producing formyl-4-acyloxy-1-butene.