A method for preparing 2,7-octadienol-1 by telomerization of butadiene

Abstract

The present invention provides a method for preparing 2,7-octadienol-1 by the telomerization of butadiene. The method utilizes a palladium catalyst, a water-soluble triphenylphosphine compound as a ligand, a ketoxime-based silane as a phase transfer catalyst, and a nitrogen-containing heterofluorene compound as a palladium stabilizer. Using this method, a butadiene conversion rate of 85% or higher, a 2,7-octadienol selectivity of 95% or higher, and a single-batch Pd atom recovery rate exceeding 95% are achieved in a reaction time of 1 hour.

Description

Technical Field

[0001] The invention belongs to the field of organic synthesis, and particularly relates to a method for preparing 2,7-octadienol-1 by telomerization of butadiene. Background Art

[0002] 1-Octanol can be used directly as a flavoring ingredient and solvent. It is also an important raw material for the preparation of synthetic fragrances such as peach aldehyde and α-hexyl-cinnamaldehyde. 1-Octanol can also be used to prepare low-foaming surfactants, Guerbet alcohols, and metal extractants (N235, TOA). The preparation processes for 1-octanol include natural fatty alcohols, the Ziegler alcohol process, the hydroformylation-hydrogenation of α-olefins, butadiene telomerization, the epoxidation-isomerization-hydrogenation of 1-octene, and the furfural process. Kuraray has developed a synthetic route for preparing 2,7-octadienol-1 through butadiene telomerization, followed by hydrogenation of 2,7-octadienol-1 to prepare 1-octanol. This route won the 1992 Technology Award from the Chemical Society of Japan.

[0003] The difficulty in preparing 2,7-octadienol-1 by the polymerization of butadiene is the loss and recovery of the precious metal catalyst. To prevent the coordination catalyst from decomposing into elemental metal at high temperatures, resulting in the loss of the precious metal catalyst, patent CN105050993A reports the use of vacuum distillation with the distillation temperature controlled below 110°C to minimize Pd loss. At the same time, water-soluble triarylphosphine is used as a ligand. After the reaction, the oil and water are separated, and the catalyst is reused with the aqueous phase after oil-water separation, reducing the catalyst loss rate. The recovery rate of Pd atoms in a single batch can reach up to 91.3%.

[0004] In order to achieve the recovery and reduction of precious metal catalysts, patent JPH03232831A reports the use of sulfonate triphenylphosphine as a ligand, the use of aliphatic alkanes to extract the reaction liquid, and the precious metal catalyst coordinated with sulfonate triphenylphosphine is reused with the aqueous phase, reducing the loss rate of the catalyst. At the same time, the addition of dimethylglyoxime can prevent the metallization of palladium.

[0005] The above schemes all use water-soluble triarylphosphine as a ligand. Although this improves the catalyst recovery rate to a certain extent, the system changes from a homogeneous phase to an oil-water two-phase, and the reaction rate is greatly reduced. The reaction time is required to be more than 4 hours. At the same time, to prevent the metallization of palladium, dimethylglyoxime is added as an auxiliary agent. Dimethylglyoxime is unstable and easily decomposes at high temperatures, posing a major safety hazard.

[0006] In summary, the existing methods for preparing 2,7-octadienol-1 still have problems such as low reaction efficiency, high safety risks, and difficulty in catalyst recovery. Summary of the Invention

[0007] The present invention aims to provide a method for preparing 2,7-octadienol-1, wherein the method has a high catalyst recovery rate, a fast reaction speed, does not use unstable substances such as dimethylglyoxime, and has a safe and reliable process.

[0008] In order to achieve the above technical effects, the present invention adopts the following technical solutions:

[0009] A method for preparing 2,7-octadienol-1 by butadiene telomerization adopts a palladium catalyst, a water-soluble triphenylphosphine compound as a ligand, a ketoxime-based silane as a phase transfer catalyst, and a nitrogen-containing heterofluorene compound as a palladium stabilizer.

[0010] The present invention uses ketoxime silane as a phase transfer catalyst and a nitrogen-containing heterofluorene compound as a palladium stabilizer. The ketoxime group (C=NO) of the ketoxime silane can be coordinated with Pd. The silane group has good oil solubility and can improve the oil solubility of a Pd catalyst coordinated with water-soluble triphenylphosphine, thereby increasing the reaction rate of butadiene polymerization. The nitrogen atom of the nitrogen-containing heterofluorene compound can be coordinated with Pd, thereby preventing metallization of Pd and reducing the loss rate of Pd.

[0011] In the present invention, the palladium catalyst contains an organic palladium salt and / or an inorganic palladium salt, preferably one or more of palladium acetylacetonate, bis(allyl)palladium, tetrakis(triphenylphosphine)palladium, palladium acetate, palladium chloride, palladium sulfate, palladium nitrate and palladium benzoate, more preferably palladium acetylacetonate and / or palladium chloride; preferably, the mass ratio of the palladium catalyst to butadiene is 1:150-1:300, preferably 1:180-1:230.

[0012] In the present invention, the ketoxime silane is a C4-C25 ketoxime silane, preferably containing one or more of methyltributyketoxime silane, vinyltributyketoxime silane, tetrabutylketoxime silane, vinyltriacetoneoxime silane, tris(methylisobutylketoxime)methylsilane and tetra(4-methyl-2-pentanoneoxime)silane, more preferably methyltributyketoxime silane and / or tris(methylisobutylketoxime)methylsilane; preferably, the mass ratio of the ketoxime silane to butadiene is 1:10-1:200, preferably 1:50-1:100.

[0013] In the present invention, the nitrogen-containing heterofluorene compound is a C8-C16 nitrogen-containing heterofluorene compound, preferably one or more of 9-azafluorene, 1,8-diazafluorene-9-one, 4,5-diazafluorene, 1-methyl-4-azafluorene-9-one, 3-amino-9-ethylazafluorene, 2,7-dibromo-4,5-azafluorene-9-one, 1-chloro-9-hydrogen-2,4,9-triazafluorene and 2-chloromethyl-9-thia-1,4-diazafluorene-4-one, more preferably 9-azafluorene and / or 4,5-diazafluorene; preferably, the mass ratio of the nitrogen-containing heterofluorene compound to butadiene is 1:50-1:300, preferably 1:100-1:200.

[0014] In the present invention, the water-soluble group of the water-soluble triphenylphosphine compound contains one or more of a sulfonic acid group, a carboxyl group, a nitrile group, an amine, and a halogen. Preferably, the water-soluble group of the water-soluble triphenylphosphine compound contains a sulfonic acid group, and more preferably, the water-soluble triphenylphosphine compound is trisulfonated triphenylphosphine TPPTS; preferably, the mass ratio of the water-soluble triphenylphosphine compound to butadiene is 1:10-1:50, preferably 1:20-1:30.

[0015] In the present invention, the reaction temperature is 70-80° C., and the reaction pressure is 2-5 MPaG.

[0016] In one embodiment, the method for preparing 2,7-octadienol-1 comprises the following steps, which are typical methods for preparing 2,7-octadienol-1 by butadiene polymerization: adding a solvent, water, a Pd catalyst, a ligand, a phase transfer catalyst and a stabilizer to a reaction vessel, and starting stirring and mixing; replacing the reactor with an inert gas; adding butadiene to the reactor; pressurizing the reactor to a set pressure with an inert gas; heating the reactor, and starting timing after heating to the set temperature; after completion, performing oil-water separation, and analyzing the reaction conversion rate, selectivity and Pd atomic content in the oil-water phase.

[0017] The solvent used in the present invention is a C6-C30 paraffin and / or cycloalkane, preferably one or more of cyclohexane, methylcyclohexane, ethylcyclohexane, isopropylcyclohexane, decalin, n-dodecane, cyclododecane, n-tetradecane, and squalane, with cyclohexane and / or methylcyclohexane being more preferred. The above solvents are typical for the polymerization of butadiene to produce 2,7-octadienol-1. The mass ratio of solvent to butadiene is 3:1-10:1, preferably 4:1-5:1. This mass ratio is typical for the mass ratio of solvents used in the polymerization of butadiene to produce 2,7-octadienol-1.

[0018] In the method for synthesizing 2,7-octadienol-1 by telomerization of butadiene according to the present invention, the mass ratio of water to butadiene can be selected from 1:1 to 3:1, preferably 1:1 to 2:1. This mass ratio is a typical ratio of water by mass when synthesizing 2,7-octadienol-1 by telomerization of butadiene.

[0019] Another object of the present invention is to provide a catalyst composition for preparing 2,7-octadienol-1.

[0020] A catalyst composition for preparing 2,7-octadienol-1 is disclosed. The catalyst composition is the catalyst composition used in the above-mentioned method for preparing 2,7-octadienol-1 by butadiene polymerization. The catalyst composition contains a palladium catalyst, a water-soluble triphenylphosphine compound as a ligand, a ketoxime-based silane as a phase transfer catalyst, and a nitrogen-containing heterofluorene compound as a palladium stabilizer.

[0021] Compared with the prior art, the present invention has the following positive effects:

[0022] The method of the present invention achieves a butadiene conversion rate of 85% or higher, a 2,7-octadien-1-ol selectivity of 95% or higher, and a single-batch Pd atom recovery rate exceeding 95% within a reaction time of 1 hour. The method of the present invention does not use unstable substances such as dimethylglyoxime, making it a safe and reliable process. DETAILED DESCRIPTION

[0023] The present invention is further described below with reference to the following examples. It should be noted that the examples do not limit the scope of protection claimed in the present invention.

[0024] Main raw material information:

[0025]

[0026]

[0027] The detection method used in the embodiment is introduced:

[0028] (1) Gas chromatography

[0029] The present invention uses gas chromatography area correction normalization analysis to determine conversion and selectivity, and the chromatographic analysis conditions are as follows:

[0030] Instrument model: Shimadzu GC2010; chromatographic column: DB-5 (30×0.32×0.25); column temperature: programmed temperature (50°C for 3 min, then increased to 100°C at a heating rate of 5°C / min, then increased to 270°C at a heating rate of 20°C / min, and maintained for 10 min); injection port temperature: 250°C; FID temperature: 300°C; N2 flow rate: 1 mL / min; H2 flow rate: 40 mL / min; septum purge (N2) flow rate: 3 mL / min; carrier gas (N2) flow rate: 1 mL / min; split injection, split ratio: 50; injection volume: 0.1 μL.

[0031] (2) Pd atomic content analysis

[0032] The metal element content was determined using an Agilent 720 inductively coupled plasma optical emission spectrometer with a power of 1.20 kW, a plasma gas flow rate of 15.0 L / min, an auxiliary flow rate of 1.50 L / min, a nebulizer flow rate of 0.80 L / min, a reading time of 5.00 s, an instrument stabilization time of 15 s, an injection delay of 50 s, a pump speed of 15 rpm, a cleaning time of 30 s, and 3 readings.

[0033] Reaction conversion rate = (1-amount of butadiene in the reaction solution / amount of butadiene added) * 100%

[0034] Recovery rate of Pd atoms = Pd atomic weight in aqueous phase / added Pd atomic weight * 100%

[0035] The reaction selectivity was analyzed by gas chromatography area calibration.

[0036] Example 1

[0037] To a 250 mL reactor, 60 g of cyclohexane, 20 g of water, 0.133 g of palladium acetylacetonate, 2 g of triphenylphosphine trisulfonate, 2 g of methyltributylidene silane and 0.4 g of 9-azafluorene were added in sequence, the stirring speed was set to 1000 rpm, and stirring and mixing were started; after the reactor was replaced with carbon dioxide three times, 20 g of butadiene was added to the reactor; the reactor was pressurized to 2 MPa (G) with carbon dioxide, and the reactor was heated through a circulating oil bath. The timing was started after the temperature reached 70°C. After the reaction lasted for 1 hour, stirring and heating were stopped, oil-water separation was performed, and the reaction conversion rate, selectivity and Pd atomic content in the oil-water phase were analyzed.

[0038] After analysis, the conversion rate of butadiene was 93.6%, the selectivity of 2,7-octadienol-1 was 96.9%, and the recovery rate of Pd atoms in a single batch was 96.7%.

[0039] Example 2

[0040] To a 500 mL reactor, 200 g of methylcyclohexane, 60 g of water, 0.067 g of palladium chloride, 0.4 g of 4-(dimethylamino)triphenylphosphine, 0.1 g of tris(methylisobutylketoneoxime)methylsilane, and 0.07 g of 4,5-diazafluorene were added in sequence, the stirring speed was set to 1000 rpm, and stirring and mixing were started; after the reactor was replaced with carbon dioxide four times, 20 g of butadiene was added to the reactor; the reactor was pressurized to 5 MPa(G) with carbon dioxide, and the reactor was heated through a circulating oil bath. The timing was started after the temperature reached 80°C. After the reaction lasted for 1 hour, stirring and heating were stopped, oil-water separation was performed, and the reaction conversion rate, selectivity, and Pd atomic content in the oil-water phase were analyzed.

[0041] After analysis, the conversion rate of butadiene was 92.1%, the selectivity of 2,7-octadienol-1 was 97.3%, and the recovery rate of Pd atoms in a single batch was 97.8%.

[0042] Example 3

[0043] To a 250 mL stainless steel reactor, 100 g of isopropylcyclohexane, 30 g of water, 0.1 g of palladium acetate, 1 g of 4-carboxybutyltriphenylphosphine, 0.4 g of vinyltributylanoximesilane, and 0.2 g of 1-chloro-9-hydrogen-2,4,9-triazafluorene were added in sequence. The stirring speed was set to 1000 rpm and stirring and mixing were started. After the reactor was replaced with carbon dioxide four times, 20 g of butadiene was added to the reactor. The reactor was pressurized to 3 MPa(G) with carbon dioxide and heated in a circulating oil bath. The timer was started after the temperature reached 75°C. After reacting for 1 h, stirring and heating were stopped, oil-water separation was performed, and the reaction conversion, selectivity, and Pd atomic content in the oil-water phase were analyzed.

[0044] After analysis, the conversion rate of butadiene was 92.5%, the selectivity of 2,7-octadienol-1 was 96.4%, and the recovery rate of Pd atoms in a single batch was 96.1%.

[0045] Comparative Example 1

[0046] A method similar to that of Example 1 was used, except that methyl tributylidene oxime silane was not added as a phase transfer catalyst. Analysis showed that after 1 h of reaction, the conversion of butadiene was 32.7%, the selectivity of 2,7-octadienol-1 was 80.1%, and the recovery rate of Pd atoms in a single batch was 95.1%.

[0047] Comparative Example 2

[0048] A method similar to that of Example 1 was used, except that 9-azafluorene was not added as a Pd stabilizer. Analysis showed that after 1 h of reaction, the conversion of butadiene was 89.3%, the selectivity of 2,7-octadienol-1 was 84.8%, and the recovery rate of Pd atoms in a single batch was 87.4%.

[0049] Comparative Example 3

[0050] A method similar to that of Example 1 was used, except that methyl tributylidene oxime silane was not added as a phase transfer catalyst and 9-azafluorene was not added as a Pd stabilizer. Analysis showed that after 1 h of reaction, the conversion of butadiene was 27.6%, the selectivity of 2,7-octadienol-1 was 74.3%, and the recovery rate of Pd atoms in a single batch was 84.5%.

[0051] Those skilled in the art will appreciate that, based on the teachings of this specification, some modifications or adjustments may be made to the present invention, and such modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A method for preparing 2,7-octadienol-1 by telomerization of butadiene, characterized in that: The method uses a palladium catalyst, a water-soluble triphenylphosphine compound as a ligand, a ketoxime-based silane as a phase transfer catalyst, and a nitrogen-containing heterofluorene compound as a palladium stabilizer; Wherein, the ketoxime silane is C4-C25 ketoxime silane; Wherein, the nitrogen-containing heterofluorene compound is a C8-C16 nitrogen-containing heterofluorene compound.

2. The method according to claim 1, characterized in that The palladium catalyst contains an organic palladium salt and / or an inorganic palladium salt.

3. The method according to claim 1 or 2, characterized in that The palladium catalyst contains one or more of palladium acetylacetonate, bis(allyl)palladium, tetrakis(triphenylphosphine)palladium, palladium acetate, palladium chloride, palladium sulfate, palladium nitrate and palladium benzoate; The mass ratio of the palladium catalyst to butadiene is 1:150-1:

300.

4. The method according to claim 3, characterized in that The palladium catalyst contains palladium acetylacetonate and / or palladium chloride; The mass ratio of the palladium catalyst to butadiene is 1:180-1:

230.

5. The method according to claim 1 or 2, characterized in that The ketoxime silane is one or more of methyltributyketoxime silane, vinyltributyketoxime silane, tetrabutylketoxime silane, vinyltriacetoneoxime silane, tris(methylisobutylketoxime)methylsilane and tetra(4-methyl-2-pentyketoxime)silane.

6. The method according to claim 5, characterized in that The ketoxime silane is methyltributyketoxime silane and / or tris(methylisobutylketoxime)methylsilane; The mass ratio of the ketoxime silane to butadiene is 1:10-1:

200.

7. The method according to claim 6, characterized in that The mass ratio of the ketoxime silane to butadiene is 1:50-1:

100.

8. The method according to claim 1 or 2, characterized in that The nitrogen-containing heterofluorene compound is one or more of 9-azafluorene, 1,8-diazafluorene-9-one, 4,5-diazafluorene, 1-methyl-4-azafluorene-9-one, 3-amino-9-ethylazafluorene, 2,7-dibromo-4,5-azafluorene-9-one, 1-chloro-9-hydrogen-2,4,9-triazafluorene and 2-chloromethyl-9-thia-1,4-diazafluorene-4-one.

9. The method according to claim 8, characterized in that The nitrogen-containing heterofluorene compound is 9-azafluorene and / or 4,5-diazafluorene; The mass ratio of the nitrogen-containing heterofluorene compound to butadiene is 1:50-1:

300.

10. The method according to claim 9, characterized in that The mass ratio of the nitrogen-containing heterofluorene compound to butadiene is 1:100-1:

200.

11. The method according to claim 1 or 2, characterized in that The water-soluble group of the water-soluble triphenylphosphine compound contains one or more of sulfonic acid group, carboxyl group, nitrile group, amine and halogen.

12. The method according to claim 11, characterized in that The water-soluble triphenylphosphine compound is a water-soluble triphenylphosphine compound whose water-soluble group contains a sulfonic acid group; The mass ratio of the water-soluble triphenylphosphine compound to butadiene is 1:10-1:

50.

13. The method according to claim 12, characterized in that The water-soluble triphenylphosphine compound is trisulfonated triphenylphosphine TPPTS; The mass ratio of the water-soluble triphenylphosphine compound to butadiene is 1:20-1:

30.

14. The method according to claim 1 or 2, characterized in that The reaction temperature is 70-80°C and the reaction pressure is 2-5 MPaG.

15. A catalyst composition for preparing 2,7-octadienol-1, the catalyst composition being the catalyst composition used in the method for preparing 2,7-octadienol-1 by butadiene polymerization as described in any one of claims 1 to 14, the catalyst composition comprising a palladium catalyst, a water-soluble triphenylphosphine compound as a ligand, a ketoxime-based silane as a phase transfer catalyst, and a nitrogen-containing heterofluorene compound as a palladium stabilizer.

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