JPH0517402A - Production of pentenoic acid ester - Google Patents

Abstract

PURPOSE:To produce pentenoic acid esters from 1,3-butadiene, an aliphatic alcohol and carbon monoxide with industrial advantage by using a new catalyst system composed of a cobalt complex prepared by addition of a small amount of an aminopyridine. CONSTITUTION:A new catalyst system composed of a cobalt complex such as cobalt diacetylacetonate, cobalt bromide or a cobalt carbonyl complex and a small amount of an aminopyridine is used. Carbon monoxide, 1,3-butadiene of formula CH2=CH-CH=CH2 and an aliphatic alcohol of formula ROH (R is aliphatic) are brought into contact with the catalyst system to synthesize the objective pentenoic acid ester of formula CH3CH=CHCH2COOR, CH3CH2CH: CHCOOR or CH2=CHCH2CH2CO0R. As the aliphatic alcohol, a 1-10C aliphatic alcohol is preferable. The aminopyridine is used preferably in an amount of 0.005-0.3mol based on 1mol 1,3-butadiene. By using the new catalyst system, pentenoic acid esters can be produced with industrial advantage.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing pentenoic acid esters. More specifically, it relates to a method for industrially advantageously producing pentenoic acid esters in the presence of a catalyst exhibiting excellent activity.

[0002]

BACKGROUND OF THE INVENTION Pentenoic acid esters are useful as intermediates for producing adipic acid, which is a raw material for producing polyhexamethylene adipamide.

In Japanese Patent Laid-Open No. 53-119816, butadiene is reacted with carbon monoxide and a C _1-4 alkanol in the presence of a tertiary nitrogen base and a cobalt carbonyl compound under heat and pressure, and then the catalyst is separated. First, a method for producing an adipic acid diester by further reacting the obtained pentenoic acid ester with carbon monoxide and a C _1-4 alkanol under heating and pressure is disclosed. In the publication,
As the tertiary nitrogen base, pyridine, methylpyridine,
For example 3-picoline or isoquinoline and trialkylamines such as trimethylamine or triethylamine are disclosed. It is also disclosed that these tertiary nitrogen bases are used in a ratio of 0.5 to 2 mol per mol of butadiene.

Bulletin of The Chemical Society of Ja
pan, Vol. 46, 524-530 (1973), a method of reacting butadiene, carbon monoxide and methanol in the presence of cobalt carbonyl and a base to produce methyl 3-pentenoate is reported. In the report, pyridine, γ-picoline, isoquinoline, 3,4 were used as bases.
-Lutidine, β-picoline, 4-vinylpyridine, α-
Picoline, quinoline, 4-aminopyridine and triethylamine are disclosed, and in the experiments 1 of each of these bases was disclosed.
It is stated that 0 g (corresponding to about 0.08 to 0.13 mol) was used per 0.1 mol of butadiene. Further, FIG. 1 of the same report discloses that the yield of methyl-3-pentenoate increases as the proportion of pyridine used increases.

Further, in JP-A-61-238756, butadiene, carbon monoxide and alcohol are described as P
A method for producing a carboxylic acid diester by reacting it in an aprotic solvent in the presence of a catalyst prepared from a d (II) compound, an organic phosphine and hydrogen chloride is disclosed.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a pentenoate ester using a novel catalyst system. Another object of the present invention is to provide a novel catalyst system exhibiting excellent catalytic activity, even though the specific basic compound constituting the catalyst system is used in a small amount relative to 1,3-butadiene. It is to provide a method for producing a pentenoic acid ester used.

Yet another object of the present invention is to increase the reaction throughput of 1,3-butadiene per unit reactor in batch reactions and per unit time in continuous reactions by using small amounts of catalyst. Another object of the present invention is to provide an industrially advantageous method for producing a pentenoic acid ester. Further objects and advantages of the present invention will be apparent from the following description.

[0008]

According to the present invention, the above objects and advantages of the present invention include the presence of a catalyst comprising 1,3-butadiene, carbon monoxide and an aliphatic alcohol, a cobalt complex and aminopyridines. It is achieved by a method for producing a pentenoic acid ester, which is characterized by contacting underneath.

As the aliphatic alcohol used in the present invention, an aliphatic alcohol having 1 to 10 carbon atoms is preferably used. The aliphatic alcohol may be linear or branched, but is preferably saturated. Examples of such aliphatic alcohols include methanol, ethanol, n-propanol, iso-propanol, n-butanol, n-pentanol and the like. Of these, methanol is preferred.

The reaction of 1,3-butadiene, carbon monoxide and an aliphatic alcohol to form a pentenoate ester is represented by the following reaction formula. _{CH 2 = CHCH = CH 2 +} CO + ROH → CH 3 CH = CHCH 2 COOR CH 3 CH 2 CH = CHCOOR CH 2 = CHCH 2 CH 2 COOR wherein, R is an aliphatic group.

As can be understood from the above reaction formula, 1,3
-Butadiene, carbon monoxide and fatty alcohols react stoichiometrically in equimolar amounts. In the present invention, carbon monoxide is 0.5 to 20 with respect to 1 mol of 1,3-butadiene.
It is preferably used in a proportion of 0 mol, and the aliphatic alcohol is 0.1 to 20 per 1 mol of 1,3-butadiene.
It is desirable to use it in a molar ratio.

The catalyst used in the present invention comprises a cobalt complex and aminopyridines. This catalyst system is new. As the cobalt complex, known compounds can be used without distinction. Preferred are, for example, cobalt diacetylacetonate, cobalt bromide, cobalt iodide, cobalt chloride, cobalt acetate, cobalt carbonate, cobalt sulfate, cobalt nitrate or Co ₂ (CO) ₈ , H 2.
Mention may be made of cobalt carbonyl complexes such as Co (CO) ₄ . Of these, cobalt carbonyl complex is particularly preferably used.

Examples of aminopyridines include 4-aminopyridine, 4-dimethylaminopyridine, and 4
-Diethylaminopyridine, 4-methylethylaminopyridine, 4-diisopropylaminopyridine, 4-di-
n-propylaminopyridine, 4-dioctylaminopyridine, 4-pyrrolidylpyridine, 4-dimethylamino-3-methylpyridine, 4-dimethylamino-3,5-
Dimethylpyridine, 3,4-diaminopyridine, 3,4-
Di (dimethylamino) pyridine, 3-aminopyridine,
Preference is given to 3-dimethylaminopyridine, 2-aminopyridine and 2-dimethylaminopyridine.

Of the above-mentioned aminopyridines, compounds from 4-aminopyridine to 4-dimethylamino-3,5-dimethylpyridine are more preferable, and 4-dimethylaminopyridine is particularly preferable. The above cobalt complex constituting the catalyst system is preferably used in a proportion of 0.005 to 0.3 mol, more preferably 0.01 to 0.2 mol, per 1 mol of 1,3-butadiene. .

The aminopyridines are preferably used in a proportion of 0.005 to 0.3 mol, more preferably 0.01 to 0.2 mol, per 1 mol of 1,3-butadiene. . The ratio of the cobalt complex and the aminopyridine compound used is preferably 0.1 to 10 mol of the aminopyridine compound per 1 mol of the cobalt complex compound, and 0.2.
It is more preferably -5 mol.

The reaction is carried out in the presence or absence of a solvent. Suitable solvents that can be preferably used are, for example, hydrocarbons such as hexane, benzene, toluene and xylene; tetrahydrofuran, dioxane, anisole, diphenyl ether, diethyl ether, dimethoxyethane, diglyme, tetraglyme, tetraethylene glycol, tetrapropylene glycol, triethylene glycol. Propylene glycol, polypropylene glycol,
Ethers such as polyethylene glycol; aniline,
Anilines such as dimethylaniline; nitrobenzene,
Nitro compounds such as nitromethane; Amide compounds such as dimethylformamide, 1-methyl-2-pyrrolidinone, dimethylacetamide; Tetramethylurea, 1,3-
Urea such as dimethyl-2-imidazolidinone and urea;
Phosphorus-containing compounds such as hexamethylphosphoric triamide, triphenylphosphine oxide and tributylphosphine oxide; sulfur-containing compounds such as sulfolane and dimethyl sulfoxide; chloroform, dichloromethane, carbon tetrachloride, dichloroethane, tribromomethane, chlorobenzene and bromobenzene. Halogenated hydrocarbons such as;
Mention may be made of esters such as methyl acetate, ethyl acetate, methyl benzoate; and ketones such as acetone, methyl ethyl ketone, cyclohexanone.

The reaction is preferably carried out at temperatures between 0 and 300 ° C, more preferably between 60 and 250 ° C. The reaction time is preferably 0.1 to 20 hours, more preferably 0.5 to 10 hours. The pressure of the reaction system is preferably 1 to 2,000 kg / cm ² , and more preferably 50 to 700 kg / cm ² .

The reaction can be carried out in the liquid phase either batchwise or continuously, the reactor being of the tank type,
It may be tubular or tower type. In order to isolate the pentenoic acid ester from the obtained reaction mixture, for example, the reaction mixture may be subjected to distillation or extraction to remove unreacted butadiene and the like, and then obtained.

The pentenoic acid ester obtained by the method of the present invention includes 3-pentenoic acid ester, 2-pentenoic acid ester,
At least one of 1-pentenoate ester is included.
These pentenoic acid esters can be converted to adipic acid diesters by a method known per se and further by reacting with carbon monoxide and an aliphatic alcohol. Adipic acid diester gives adipic acid by hydrolysis. Hereinafter, the present invention will be described in more detail with reference to Examples.

[0020]

Example 1 1 mmol of Co ₂ (CO) ₈ (2 mmol as Co), 2 mmol of 4-dimethylaminopyridine, 50 mmol of butadiene, 100 mmol of methanol and 6.4 g of toluene were charged into an autoclave, and then monoxide was added. Carbon was pressed up to 100 kg / cm ² . 130 ° C
After heating for 2 hours, the pressure in the reaction system was 120 kg /
rose to cm ² . It was then cooled and then depressurized. The obtained reaction mixture was analyzed by gas chromatography to find that, based on butadiene, 9.2% of methyl 3-pentenoate, 0.5% of methyl 2-pentenoate and 0.2% of methyl pentanoate were formed. I found out that

Example 2 Example 2 was repeated except that the amount of 4-dimethylaminopyridine used was changed as shown in Table 1 below. The results are shown in Table 1.

Comparative Example 1 Example 1 was repeated except that pyridine was used instead of 4-dimethylaminopyridine. The results are shown in Table 1.

[0023]

[Table 1]

Reference Example 1 The reaction was carried out in the same manner as in Example 1, cooled and depressurized, then carbon monoxide was injected into the reaction system to 150 kg / cm ² , and then heated at 170 ° C. for 4 hours. Cooled, depressurized and the resulting reaction mixture analyzed by gas chromatography. As a result, it was found that 6% of dimethyl adipate was formed based on the butadiene used.

[0025]

EFFECTS OF THE INVENTION According to the present invention, excellent catalytic activity is exhibited by using a specific basic compound in a small proportion as one component of a catalyst system, and therefore, a pentenoic acid ester can be produced industrially advantageously. There are advantages.

Claims (3)

[Claims] 1. A process for producing a pentenoic acid ester, which comprises contacting 1,3-butadiene, carbon monoxide and an aliphatic alcohol in the presence of a catalyst composed of a cobalt complex and aminopyridines. 2. The method according to claim 1, wherein the aliphatic alcohol is an aliphatic alcohol having 1 to 10 carbon atoms. 3. Aminopyridines are 1,3-butadiene
The method according to claim 1, which is used in a ratio of 0.005 to 0.3 mol per mol.