JPH0669971B2 - Method for producing 3-methylbutene-1 - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a method for producing 3-methylbutene-1, which is a raw material of a useful polymer.

[Conventional technology]

Conventionally, it is known that 3-methylbutene-1 is produced by partial hydrogenation of isoprene. However, when isoprene is catalytically hydrogenated, in most cases, paraffin (2 -Methylbutane). Even if partial hydrogenation of hydrogenating only one double bond is successful, the main component is hydrogenation of 1,4-adduct 2-methylbutene-2 and double bonds with less steric hindrance. 2-
Methylbutene-1 and the desired 3-methylbutene-1
The generation ratio of is very small.

The relatively good selectivity resulting example partially hydrogenated by 3-methylbutene-1 of isoprene, _{^{(b) Co (CN ▲) 3- 5}} ▼ method according catalyst (ORa between et al, B
ull.Chem.Soc.Jpn, 45 , 2723 (1972)), (b) CoBr (PPh ₃ ) ₃ -BF ₃ · OEt ₂ catalyst method (Mizorogi et al., Chem. Lett., 847 (1976)), and (C) Method using PdCl ₂ (PPh ₃ ) ₂ -SnCl ₂ catalyst (Itaya et al., Ind.Eng.Chem.Prod.Res.Dev. 11 , No.2,146 (197
2)) etc. are known.

[Problems to be solved by the invention]

However, among these, the methods of (a) and (c) do not have sufficiently high selectivity for 3-methylbutene-1, and the method of (b) has insufficient reaction rate and catalytic activity. It is not enough to be used effectively.

On the other hand, there is a method of partially hydrogenating isoprene in the presence of a catalyst composed of cobalt compound-phosphorus compound-organoaluminum compound (Japanese Patent Publication No. 45-22322), but the production ratio of 3-methylbutene-1 is at most 15%. is there.

Moreover, among these, even in a reaction system having a high selectivity for 3-methylbutene-1, when the conversion of isoprene becomes high, the isomerization reaction of the produced 3-methylbutene-1 rapidly occurs, and as a result, the main component is 2 It had the drawback of becoming methylbutene-2.

[Means for solving problems]

The present inventors have found that 3-methylbutene-1 is produced at a high selectivity and a high reaction rate by the partial hydrogenation reaction of isoprene, and even when the conversion of isoprene is high, 3
The present invention has been achieved as a result of extensive studies to find out a catalyst system and reaction conditions capable of maintaining high selectivity of -methylbutene-1.

That is, the present invention is a method for producing 3-methylbutene-1 by partial hydrogenation of isoprene in the presence of a catalyst composed of a cobalt compound, an organic phosphine compound, and an aluminum compound, wherein an organic phosphine for 1 mol of cobalt atom in the cobalt compound is produced. A method for producing 3-methylbutene-1, wherein the number of moles of phosphorus atom in the compound is in the range of more than 20 and 500 or less, and a cobalt compound, an organic phosphine compound, an aluminum compound, and a boron halide compound, and In the method for producing 3-methylbutene-1 by partial hydrogenation of isoprene in the presence of a catalyst consisting of a protonic acid having a pKa of 1 or less, 1 mol of cobalt atom in the cobalt compound is used.
To the number of moles of phosphorus atom in the organic phosphine compound
Characterized by a range of more than 20 and less than 500 3
A method for producing methylbutene-1 is as a gist.

Hereinafter, the present invention will be described in more detail.

In the process of the invention, a catalyst system consisting of a cobalt compound, an organic phosphine compound and an aluminum compound is used.

As the cobalt compound, cobalt chloride, cobalt sulfate, cobalt nitrate, cobalt carbonate, cobalt acetate, cobalt formate, cobalt naphthenate, cobalt oleate,
Salts of cobalt octanoate, cobalt cyanide, cobalt fluoride, cobalt bromide, cobalt iodide, etc .; chelate compounds of bis (acetylacetonato) cobalt, tris (acetylacetonato) cobalt, etc .; chlorotris (triphenylphosphine) Examples thereof include organic phosphorus compound complexes such as cobalt, bromotris (triphenylphosphine) cobalt, dichlorobis (triphenylphosphine) cobalt, and dibromobis (triphenylphosphine) cobalt.

Examples of the organic phosphine compound include triphenylphosphine, tris (p-methoxyphenyl) phosphine, tris (o-methoxyphenyl) phosphine, tris (p-trimethylsilylphenyl) phosphine, tri-p-tolylphosphine. And triarylphosphines such as tri-o-tolylphosphine; tri-n-butylphosphine, tri-n-propylphosphine, tri-iso-
Trialkylphosphines such as propylphosphine; Triaralkylphosphines such as tribenzylphosphine; Diphenyl-n-propylphosphine, diphenyl-iso
-Propylphosphine, 1-diphenylphosphino-2
Examples include mixed alkylaryl phosphines such as -trimethylsilylethane and 1,2-bis (diphenylphosphino) ethane; polymer phosphines such as crosslinked oligomers of triphenylphosphine.

Examples of the aluminum compound include trimethyl aluminum, triethyl aluminum, tri-iso-butyl aluminum, tri-n-butyl aluminum, tri-n-propyl aluminum, tri-n-hexyl aluminum, diethyl aluminum hydride, di-iso.
-Butyl aluminum hydride, diethyl aluminum chloride, di-iso-butyl aluminum chloride, diethyl aluminum bromide, ethyl aluminum dichloride, iso-butyl aluminum dichloride, ethyl aluminum dibromide, ethyl aluminum sesquichloride, iso-butyl aluminum sesquichloride, ethyl aluminum Organic aluminum compounds such as sesquibromide; inorganic aluminum compounds such as aluminum chloride and aluminum bromide.

As the aluminum compound, it is preferable to combine the above-mentioned organic aluminum compound and the inorganic aluminum compound or to use a plurality of organic aluminum compounds in combination. Further, it is more preferable to use an aluminum compound containing a halogen atom, that is, an organic aluminum compound or an inorganic aluminum compound containing a halogen atom, and an organic aluminum compound containing no halogen atom in combination.

In the present invention, it is effective to further use a boron halide compound and / or a protonic acid having a pKa of 1 or less as a catalyst component.

Examples of the boron halide compound include boron trifluoride,
Boron trichloride, boron tribromide, hydrofluoric boron trifluoride _{etherate, (BF 3 · OEt 2)} , three Hutu boron and secondary methanol product (BF ₃ · 2CH ₃ OH), and the like.

Further, as the protonic acid with pKa1 or less, inorganic protonic acids such as sulfuric acid, hydrochloric acid, hydrobromic acid, nitric acid, phosphoric acid, perchloric acid, tetrafluoroboric acid and thiocyanic acid; trifluoroacetic acid, trichloroacetic acid, trichloromethane Sulfonic acid,
Organic protic acids such as trifluoromethane sulfonic acid and p-toluene sulfonic acid may be mentioned. Among the above, the organic protonic acid is more preferably used.

Further, in the present invention, the number of moles of phosphorus atom in the organic phosphine compound relative to 1 mol of cobalt atom in the cobalt compound is in the range of more than 20 and 500 or less.

The cobalt compound is usually 1 to 0.00001 mol, preferably 0.1 to 0.01 as a cobalt atom, based on 1 mol of the raw material isoprene.
It is added in the range of 001 mol. Then, the organic phosphine compound is added in the range of more than 20 mol and 500 mol or less as a phosphorus atom with respect to 1 mol of the cobalt atom in the cobalt compound. When it is 20 mol or less, the selectivity of 3-methylbutene-1 which is a target product tends to be lowered when the conversion rate of the raw material isoprene is increased.

The aluminum compound is usually 1 to 1 mol as an aluminum atom for 1 mol of the cobalt atom in the above cobalt compound.
It is added in the range of 100 mol, preferably in the range of 3 to 20 mol.

Furthermore, when a boron halide compound is used, it is usually 1 to 10 per 1 mol of the cobalt atom in the cobalt compound.
It is used in the range of 0 mol, preferably 1 to 10 mol. Also p
When a protic acid having a Ka of 1 or less is used, it is usually used in an amount of 1 to 100 mol, preferably 1 to 10 mol, per 1 mol of cobalt atom in the cobalt compound.

As the reaction temperature, a temperature of 50 ° C. or lower is usually adopted.
At a temperature higher than 50 ° C, the production ratio of the above-mentioned isomers other than the desired product, 3-methylbutene-1, increases. The reaction temperature is preferably in the range of -20 ° C to 50 ° C, more preferably -5 ° C to 45 ° C.

The reaction pressure is usually from normal pressure to 50 kg / cm ² .

The reaction is usually performed in the presence of a solvent. As a solvent,
Any solvent inert to the reaction may be used, for example, toluene,
Chlorobenzene, bromobenzene, etc. can be used.

The reaction can be carried out in a batch system, a semi-continuous system, or a continuous system. The reaction product, that is, the desired 3-methylbutene-1, its isomer, 2-methylbutane, etc., can be separated by a conventional separation method such as distillation, extraction,
It can be separated by adsorption or the like. Especially when separated by distillation, the distillation residue can be recycled as a catalyst liquid.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist thereof is not exceeded.

The abbreviations represent the following, and the reaction rate and production rate were calculated by the following formulas.

IP: Isoprene 3MB1: 3-Methylbutene-1 2MB1: 2-Methylbutene-1 2MB2: 2-Methylbutene-2 2MB: 2-Methylbutane (*) Reduction products: 3MB1, 2MB1, 2MB2 and 2MB Comparative Example-1 Cobalt (II) acetylacetonate dihydrate 59mg (0.2mmol) and triphenylphosphine 157mg (0.6mmol) in a 100ml volumetric flask. Was charged, the system was thoroughly replaced with nitrogen, and then 20 ml of chlorobenzene was added. To the chlorobenzene solution, 0.42 ml (0.46 mmol) of a 14.5 wt% toluene solution of triethylaluminum was added dropwise while stirring under ice cooling. Furthermore, ethyl aluminum sesquichloride 18.4
0.52 ml (0.34 mmol) of wt% toluene solution was added dropwise, and finally 0.3 ml (3.0 mmol) of isoprene was added, and after replacing the system with hydrogen, hydrogen was introduced at atmospheric pressure while vigorously stirring under ice cooling. did. After the introduction, hydrogen absorption started and hydrogenation reaction proceeded. When the reaction liquid was analyzed by gas chromatography when the hydrogen absorption amount was about 90% of the theoretical amount, the IP reaction rate was 90%.
%, The production rate of 3MB1 was 82%. The hydrogenation reaction was further continued, and when the absorption of a hydrogen amount close to the theoretical amount was observed, the reaction liquid was analyzed again.
The generation rate of 3MB1 almost disappeared at 0.4%, while the generation rate of 2MB2 increased to 87.9%. The production ratio of reduction products other than 3MB1 and 2MB2 was 7.6% for 2MB1 and 4.1% for 2MB.

Example-1 A reaction was carried out in exactly the same manner as Comparative Example-1 except that the amount of triphenylphosphine used was increased to 1.31 g (5 mmol).

When the reaction rate was analyzed by gas chromatography when the IP reaction rate was 90%, the 3MB1 production ratio was the same as in Comparative Example-1.
It was 82%, but when the IP reaction rate was further increased and absorption of a hydrogen amount close to the theoretical amount was observed, the reaction solution was analyzed and the IP reaction rate was 99.4% and the 3MB1 production ratio was 82%. Atsuta
At this time, the production ratio of other reduction products is 2MB1 4.6%, 2MB
2 was 13.8% and 2MB was 0.1%.

Example-2 2.62 g (10 mmol) of triphenylphosphine and 0.60 ml (0.46 mmol) of a 10.0 wt% toluene solution of triethylaluminum as a toluene solution of triethylaluminum.
In addition, 10.0% of ethylaluminum sesquichloride as a toluene solution of ethylaluminum sesquichloride.
The reaction was performed in the same manner as in Example-1 except that 0.96 ml (0.34 mmol) of wt% toluene solution was used. The reaction was stopped when the absorption of the amount of hydrogen close to the theoretical amount was observed, and the reaction solution was analyzed by gas chromatography.

IP reaction rate 98.1% 3MB1 generation rate 78.4% 2MB1 〃 6.4% 2MB2 〃 15.1% 2MB 〃 0.1% Example-3 Triethylaluminum as a toluene solution 10.0wt% Triethylaluminum solution 0.60ml (0.46mm
The reaction was carried out in the same manner as in Example-1 except that 52 mg (0.39 mmol) of aluminum chloride was added to ol) instead of the toluene solution of ethylaluminum sesquichloride.
The reaction was stopped when the absorption of the amount of hydrogen close to the theoretical amount was observed, and the reaction solution was analyzed by gas chromatography. The following results were obtained.

IP response rate 96.8% 3MB1 generation rate 83.8% 2MB1 〃 4.8% 2MB2 〃 11.3% 2MB 〃 0.1% Example-4 Using a 1-volume flask, the amount of cobalt (II) acetylacetonate dihydrate used 1.47 g (5.0 mmol)
The amount of triphenylphosphine used was 32.75 g (125 mmo
l), the addition amount of chlorobenzene to 250 ml, 10.0 wt% toluene solution of triethylaluminum as a toluene solution of triethylaluminum 15.1 ml (11.4 mmol), and ethylaluminum sesquichloride as a toluene solution of ethylaluminum sesquichloride 15.3 wt%. % Toluene solution 15.5 ml (8.55 mmol) and the reaction was performed in the same manner as in Example 1 except that the amount of isoprene used was changed to 100 ml (1.0 mol), and absorption of hydrogen amount close to the theoretical amount was observed. When the reaction was stopped at that point, the reaction solution was analyzed by gas chromatography, and the following results were obtained.

IP reaction rate 99.9% 3MB1 generation rate 77.8% 2MB1 〃 4.2% 2MB2 〃 17.9% 2MB 〃 0.1% Comparative example-2 Triethylaluminum toluene solution 10.0 wt% Triethylaluminum 10.0% toluene solution 0, 60 ml (0.46
mmol) followed by 55 μm (0.44 mmol) of boron trifluoride etherate without using a toluene solution of ethylaluminum sesquichloride, and then isoprene was added in the same manner as in Comparative Example-1. Done. When the reaction solution was analyzed when the amount of absorbed hydrogen was about 85% of the theoretical amount, the IP reaction rate was 85% and the 3MB1 production ratio was 85%. When the amount of absorption was observed, the reaction solution was analyzed and the following results were obtained.

IP reaction rate 92% 3MB1 generation rate 0.5% 2MB1 〃 6.8% 2MB2 〃 89% 2MB 〃 3.2% Example-5 Comparative Example-2 except that the amount of triphenylphosphine used was increased to 1.31g (5.0mmol) When the reaction was carried out in the same manner as in Example 3, when the IP reaction rate was 85%, the 3MB1 production ratio was Comparative Example-2.
The same result was obtained, but the reaction solution was analyzed when the IP reaction rate was further increased and absorption of a hydrogen amount close to the theoretical amount was observed, and the following results were obtained.

IP reaction rate 92% 3MB1 generation rate 44% 2MB1 〃 6.4% 2MB2 〃 48% 2MB 〃 1.6% Comparative example-3 Comparison was made except that trifluoromethanesulfonic acid 50 mg (0.33 mmol) was used in place of boron trifluoride etherate. The reaction was carried out in the same manner as in Example-2. When the reaction solution was analyzed when the amount of absorbed hydrogen was about 90% of the theoretical amount, the IP reaction rate was 90% and the 3MB1 production ratio was 89.4%. When the amount of absorption was observed, the reaction solution was analyzed and the following results were obtained.

IP reaction rate 99% 3MB1 generation rate 0.4% 2MB1 〃 8% 2MB2 〃 88% 2MB 〃 3.6% Example-6 Comparative example-3 except that the amount of triphenylphosphine used was increased to 1.31g (5.0mmol) -3 When the reaction was carried out in the same manner as in Example 3, when the IP reaction rate was 90%, the 3MB1 production ratio was Comparative Example-3.
The same result was obtained with 89.4%, but when the IP reaction rate was further increased and the absorption of hydrogen amount close to the theoretical amount was observed, the reaction solution was analyzed and the following results were obtained.

IP reaction rate 99.2% 3MB1 generation rate 56% 2MB1 〃 11% 2MB2 〃 31% 2MB 〃 2% [Effect of the invention] According to the method of the present invention, isoprene, which is an inexpensive raw material, can be selectively produced at a high yield. Since the reaction rate is sufficiently fast to produce 3-methylbutene-1, and the high selectivity of 3-methylbutene-1 can be maintained even at a high isoprene reaction conversion rate, the method of the present invention is industrial Extremely high value.

Claims (2)

[Claims] 1. A method for producing 3-methylbutene-1 by partially hydrogenating isoprene in the presence of a catalyst comprising a cobalt compound, an organic phosphine compound and an aluminum compound, wherein 1 m of cobalt atom in the cobalt compound is used.
A method for producing 3-methylbutene-1, wherein the number of moles of phosphorus atom in the organic phosphine compound relative to ol is in the range of more than 20 and 500 or less. 2. Isoprene is partially hydrogenated in the presence of a catalyst consisting of a cobalt compound, an organic phosphine compound, an aluminum compound, and a boron halide compound and / or a protic acid having a pKa of 1 or less to produce 3-methylbutene-1. The method for producing 3-methylbutene-1 characterized in that the number of moles of phosphorus atom in the organic phosphine compound relative to 1 mol of cobalt atom in the cobalt compound is more than 20 and 500 or less.