JP2990850B2 - Palladium compound and method for producing alkoxyalkadiene using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The palladium compound provided by the present invention is useful as a component of a telomerization catalyst for promoting a telomerization reaction between an aliphatic conjugated diene and an alcohol. The alkoxyalkadiene obtained by the telomerization reaction is used as a raw material for polymer and organic synthesis, a solvent, particularly as a paint or varnish composition.

[0002]

2. Description of the Related Art It is known that an alkoxyalkadiene is formed by a telomerization reaction between an alcohol and an aliphatic conjugated diene. Conventionally, this reaction is carried out in the presence of a palladium compound. As the palladium compound, a zero-valent palladium complex (for example, Japanese Patent Publication No. 48-42606), a divalent palladium salt and a complex (for example, Japanese Patent Publication No. 47-20205)
And Japanese Patent Publication No. 49-31965).

[0003] However, zero-valent and divalent palladium complexes are very expensive, and many compounds lack stability, and cannot be implemented on an industrial scale. In addition, divalent palladium salts have lower reactivity than zero-valent and divalent palladium complexes. Therefore, a stable and highly reactive catalyst is desired for the telomerization reaction of an aliphatic conjugated diene.

[0004]

An object of the present invention is to carry out a telomerization reaction between an aliphatic conjugated diene and an alcohol,
It is an object of the present invention to provide a palladium compound useful as a component of a telomerization catalyst having high reaction activity when producing an alkoxyalkadiene.

Another object of the present invention is to provide a telomerization catalyst having the palladium compound.

A further object of the present invention is to provide a method for producing an alkoxyalkadiene by reacting an aliphatic conjugated diene with an alcohol using the telomerization catalyst.

[0007]

That is, the present invention provides a compound represented by the following general formula (1):

[0008]

Embedded image (Wherein R 2 represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a halogen atom), a telomerization catalyst comprising the palladium compound and a phosphine compound, and an alkoxy using the catalyst. The present invention relates to a method for producing alkadiene.

The features of the palladium catalyst of the present invention are that it is easier to prepare and extremely stable than conventional catalysts, has a high reaction rate, and has excellent catalytic activity.

Hereinafter, the present invention will be described in detail.

The telomerization catalyst used in the present invention is, for example, a compound represented by the general formula (2) in the presence of a solvent:

[0012]

Embedded image (Wherein R2 represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a halogen atom), and can be easily synthesized by salt exchange between a compound represented by the following formula and a palladium salt. The obtained palladium compound is separated by filtration at room temperature and dried. Examples of the solvent include alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ethers such as diethyl ether and tetrahydrofuran, and water. More than one species is used.

The palladium salt may be prepared by any method as long as it is in a divalent state dissolved in a solution. In the case of palladium chloride, it is difficult to dissolve it alone in water. An aqueous solution containing a compound such as sodium or potassium chloride, a nitric acid solution, or the like is used. The amount of the palladium salt used is 1 to 3 times, preferably 1.5 to 2.5 times the mol of the compound of the general formula (2), and the reaction temperature is in the range of 10 to 80 ° C. However, it is easy to operate at room temperature. The reaction is preferably performed under an inert gas such as nitrogen.

R2 is exemplified by a hydrogen atom, an alkyl group such as methyl, ethyl and isopropyl, and a halogen such as chlorine, bromine, fluorine and iodine.

The general formula (2) constituting the telomerization catalyst
The amount of the palladium compound represented by is usually 0.00001 to 1 g atom, preferably 0.000 g, in terms of palladium atom per mole of the aliphatic conjugated alkadiene.
Used in the range of 1-0.5 gram atom.

The phosphine compound used as a co-catalyst in the present invention includes tributylphosphine, tricyclohexylphosphine, trialkylphosphine such as tri-n-octylphosphine, triphenylphosphine, and the like.
Tri (o-tolyl) phosphine, tri (m-tolyl) phosphine, tri (p-tolyl) phosphine, diphenyl-p-chlorophenylphosphine, tris (p-methoxyphenyl) phosphine, sodium diphenylphosphinobenzene-m-sulfonate, 3 sodium Triarylphosphine such as mutris (m-sulfophenyl) phosphine, tris (carboxyphenyl) phosphine, bis (carboxyphenyl) phenylphosphine, carboxyphenyldiphenylphosphine, 1,2-bis (diphenylphosphino) ethane, 1, Examples thereof include bidentate phosphines such as 3-bis (diphenylphosphino) propane and 1,4-bis (diphenylphosphino) butane. One or more of these can be used. These phosphine compounds are generally used in an amount of 0.1 to 100 mol, preferably 0.2 to 20 mol, per gram atom of palladium.

The aliphatic conjugated alkadiene used in the present invention is 1,3-butadiene, 2-ethyl-1,3
Examples thereof include compounds having 4 to 8 carbon atoms, such as -butadiene, 2,3-dimethyl-1,3-butadiene, isoprene, 1,3-pentadiene, chloroprene, and 1,3-octadiene. Butadiene is particularly preferred, and an inexpensive BB fraction obtained from petroleum cracking gas can be used.

The other starting materials, alcohols, include those having 1 to 8 carbon atoms such as methanol, ethanol, n-propanol, butanol, 2-ethylhexanol and ethylene glycol. Alicyclic alcohols such as aliphatic alcohols, cyclohexanol and methylcyclohexanol;
And aromatic alcohols such as phenol, phenol and benzyl alcohol.

A solvent is not necessarily required for the reaction between the aliphatic alkadiene and the alcohol, but a solvent inert to the reaction can be used. For example, ketones such as acetone and methyl ethyl ketone, and dioxane and the like can be used. Ethers, nitriles such as acetonitrile and propionitrile, hydrocarbons such as benzene, cyclohexane and n-hexane, sulfoxides such as dimethyl sulfoxide,
Examples include nitro compounds such as nitrobenzene and nitromethane, acetamide, propionamide, N, N-dimethylformamide, and N, N-dimethylacetamide.

The reaction temperature is usually in the range of 0 ° C. to 150 ° C., preferably 30 ° C. to 120 ° C. The reaction pressure is not particularly limited, and pressure conditions under normal pressure or under pressure can be appropriately selected and employed. The reaction time is from 0.1 to 10 hours, preferably from 0.2 to 6 hours. The telomerization reaction can be carried out by a continuous system or a batch system, but the industrial system is preferably a continuous system.

[0021]

When the palladium compound of the present invention is used as a catalyst component in a telomerization reaction, it is stable and has high catalytic activity. The alkoxy alkadiene obtained by the reaction is a compound useful as a polymer and an organic synthesis raw material, a solvent, especially a paint or varnish composition.

[0022]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

Example 1 A 500 ml three-necked flask equipped with a dropping funnel, a stirrer, and a nitrogen gas inlet / outlet was purged with nitrogen, and then ethanol: water = 3 in which 1 g (6.09 mmol) of hinokitiol was dissolved. 80 ml of the mixed solution of No. 1 was charged. To this, 40 ml (3.05 mmol) of an aqueous solution of K ₂ PdCl ₄ was slowly dropped with a dropping funnel and reacted for 1 hour. The resulting precipitate is filtered off with a membrane filter, washed with water,
After methanol washing and vacuum drying, 0.89
g of a yellow solid were obtained.

The elemental analysis values and IR spectrum of the palladium compound obtained by the above synthesis are shown in Table 1 and FIG.

[0025]

[Table 1] Example 2 Palladium compound 42 of formula 5 in a 50 ml autoclave
mg (0.12 mmol), triphenylphosphine 6
3 mg (0.24 mmol) and 16 ml of methanol are added, and the atmosphere is replaced with nitrogen. Next, 12 g of butadiene was added, and the mixture was reacted at 75 ° C. for 3 hours at 7 kg / cm ² G by nitrogen pressure. The conversion of butadiene was 93% and the selectivity was as follows.

[0026]

Embedded image 1-methoxy-2,7-octadiene (1-OMe) 78.7% 3-methoxy-1,7-octadiene (3-OMe) 8.1% Butadiene dimer (Dimer) 12.8% Example 3 When the procedure was performed in the same manner as in Example 2 except that the palladium compound was changed to 52 mg (0.12 mmol) of the palladium compound obtained in Example 1, the conversion of butadiene was 95%.
% And selectivity were as follows.

1-OMe 78.2% 3-OMe 8.0% Dimer 13.5% Comparative Example 1 A palladium compound was prepared using 27 mg of palladium acetate (0.12%).
The reaction was carried out in the same manner as in Example 2 except that the conversion to butadiene was 86%, and the selectivity was as follows.

1-OMe 79.0% 3-OMe 8.6% Dimer 9.8% Examples 4,5 Examples except that triphenylphosphine was replaced by the phosphine compound (0.24 mmol) shown in Table 2. Performed similarly to 3. Table 2 shows the results.

[0029]

[Table 2] Examples 6 and 7 The same procedure as in Example 2 was carried out except that triphenylphosphine was replaced with a phosphine compound shown in Table 3. Table 3 shows the results
Shown in

[0030]

[Table 3]

[Brief description of the drawings]

FIG. 1 shows an IR spectrum (KBr) of the palladium compound obtained in Example 1.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C07F 15/00 C07C 41/06 C07C 43/15 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] [Claim 1] (In the formula, R1 represents an alkyl group having 1 to 3 carbon atoms or halogen.) ## STR2 ## (Wherein, R 2 represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a halogen). A telomerization catalyst comprising a palladium compound represented by the formula: 3. The method according to claim 2, wherein the reaction between the aliphatic conjugated diene and the alcohol produces an alkoxyalkadiene.
A method for producing an alkoxy alkadiene, comprising using the catalyst for telomerization described in 1 above.