Preparation method of high-performance fuel cage hydrocarbon compound

Abstract

The invention discloses a preparation method of a high-performance fuel polyhedral oligomeric hydrocarbon compound, the specific structure of the high-performance fuel polyhedral oligomeric hydrocarbon compound is shown in the specification, and the polyhedral oligomeric hydrocarbon compound is specifically an adamantane olefin dimer, called BADH for short. Adamantanone is used as an initial raw material, a TiClx / M reducing agent system and organic alkali are used, McMurry coupling reaction is carried out, and a cage-shaped hydrocarbon compound with high density and high volume calorific value is prepared through one-step reaction and can be used as a solid propellant of rocket fuel. In addition, the synthesis process is simple, the reaction time is short, the cost is low, and the application prospect is relatively high. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the technical field of caged hydrocarbon compound preparation, and in particular relates to a method for preparing a high-performance fuel caged hydrocarbon compound. Background Art

[0002] Aerospace technology is a concentrated reflection of a country's comprehensive national strength and scientific and technological innovation capabilities. With the development of new high-performance aerospace vehicles (high speed, large payload, long range and strong maneuverability, etc.), higher requirements are also put forward for their propellants, that is, high volume calorific value and high density, and it is expected to quickly and cost-effectively improve the propulsion performance of existing aircraft, so its synthesis and research and development are of great significance. Among them, caged hydrocarbon compounds have high ring tension and density, and are a high-performance fuel with good application prospects.

[0003] There are also studies on the caged hydrocarbon compound adamantane olefin dimer BADH in the prior art. However, there are problems of long reaction time and low yield. (CN103204758A) discloses that adamantane ketone is used as the starting material, a combined reducing agent TiCl4 / LiAlH4 is used in a tetrahydrofuran solvent, and a carbonyl reduction coupling reaction is carried out under the action of a catalyst pyridine to synthesize BADH, with a yield of about 87% and a product purity of more than 98%, but it takes 24 hours to react, and the cycle is relatively long. (Yeung LL, YipY C, Luh T Y. Chem Inform Abstract: Desulfurization-Dimerization of Dithioacetals with W (CO) 6. [J]. Journal of the Chemical Society, Chemical Communications, 1987, 18 (52). 981-983.) Using adamantane ketal derived from adamantane ketone as the raw material, reflux in chlorobenzene for 24 hours, and use hexacarbonyl tungsten to catalyze its coupling to obtain adamantane olefin dimer, with a yield of 71%. The reaction raw materials used in this method need to be prepared from adamantane ketone, the thiol reagent used has a strong odor, the overall preparation process is cumbersome, and the yield is low. In addition, the hexacarbonyl tungsten used is expensive and costly.

[0004] Therefore, the existing method for synthesizing high-performance fuel cage hydrocarbon compound BADH still needs to be further improved, the reaction time needs to be further shortened, the yield needs to be further increased, and the product purity needs to be further improved. Summary of the invention

[0005] The purpose of the present invention is to shorten the reaction time for synthesizing a high-performance fuel cage hydrocarbon compound adamantane olefin dimer BADH, and to improve the selectivity, yield and purity of the target product.

[0006] In order to solve the problems existing in the prior art, the present invention provides a method for preparing a caged hydrocarbon compound, using adamantanone as a starting material and TiCl x / M reducing agent system and organic base are used as catalysts to make adamantane ketone undergo McMurry coupling reaction in a solvent in an inert atmosphere to obtain a caged hydrocarbon compound;

[0007] Before the reaction, TiCl x / M reducing agent system for reflux reaction;

[0008] TiCl x / M reducing agent system is TiCl x / Zn,TiCl x / Zn-Cu,TiCl x / Zn-Ag,TiCl x / Fe,TiCl x / Fe-Cu,TiCl x / Mg, TiCl x / K, TiCl x / Na, TiCl x / One or more of Li;

[0009] x is 3 or 4, preferably 4;

[0010] The caged hydrocarbon compound is adamantane olefin dimer BADH,

[0011]

[0012] The molecular formula of the adamantane olefin dimer BADH is C 20 H 28 .

[0013] According to a specific embodiment of the present invention, the reflux reaction is carried out at 80-90° C. for 0.5-3 h, preferably 1-2.5 h.

[0014] According to a specific embodiment of the present invention, TiCl x TiCl / M reducing agent system x The molar ratio of the reactant adamantanone is 1 to 2.0:1, preferably 1.1 to 2.0:1, and more preferably 1.1 to 1.5:1.

[0015] According to a specific embodiment of the present invention, TiCl x TiCl / M reducing agent system x The molar ratio of the metal M is 1:1.5 to 3, preferably 1:2.1 to 3, and more preferably 1:2.1 to 2.5.

[0016] The present invention selects a specific reducing agent catalyst system and controls the ratio of the reducing agent catalyst system to the reactants and the metal M at the same time, and simultaneously uses a reflux reaction to activate the reducing agent catalyst system, thereby making the activity higher, shortening the reaction time, and achieving higher reaction efficiency and product selectivity.

[0017] According to a specific embodiment of the present invention, the above preparation method specifically comprises the following steps:

[0018] (1) Add metal M powder and solvent into the reactor, and slowly add titanium reagent TiCl at -20 to 0°C under an inert atmosphere. x ;

[0019] (2) Titanium reagent TiCl x After the addition is completed, slowly warm to room temperature and reflux at 80-90°C for 0.5-3h;

[0020] (3) cooling again to 0°C, adding dropwise an organic base reagent, and then adding dropwise a solution of adamantane ketone and a solvent, and reflux at 80 to 90°C for 5 to 10 hours;

[0021] (4) Post-treating the reaction solution to obtain adamantane olefin dimer BADH.

[0022] According to a specific embodiment of the present invention, the inert atmosphere is preferably a nitrogen atmosphere.

[0023] According to a specific embodiment of the present invention, post-processing comprises the following steps:

[0024] (1) obtaining a crude product by extraction;

[0025] (2) Recrystallizing the crude product under vacuum conditions to obtain a high-purity target product, adamantane olefin dimer BADH; wherein the solvent used for recrystallization is one or more of petroleum ether, n-hexane, and methylcyclohexane.

[0026] The present invention adopts vacuum conditions and uses a solvent with low polarity (one or more of petroleum ether, n-hexane, and methylcyclohexane) to obtain a target product with high purity in a short time and at a low cost.

[0027] According to a specific embodiment of the present invention, the extraction step comprises: adding sodium carbonate or sodium bicarbonate solution to the reaction solution, then using dichloromethane as an extractant for extraction, drying the obtained organic phase with anhydrous sodium sulfate, and then removing the solvent in vacuo to obtain a crude product; preferably, the concentration of the sodium carbonate or sodium bicarbonate solution is 5 to 20wt%, more preferably 10wt%.

[0028] According to a specific embodiment of the present invention, the solvent in step (1) or step (3) is one or more of tetrahydrofuran, 1,4-dioxane, and ethylene glycol dimethyl ether.

[0029] According to a specific embodiment of the present invention, the ratio of the reactant adamantanone to the solvent is 1:10-1:35 (g / mL).

[0030] According to a specific embodiment of the present invention, the organic base is one or more of pyridine, 2-chloropyridine, 2-bromopyridine, 2-fluoropyridine, 2,4-dichloropyridine, 2,6-dichloropyridine, 1-bromo-2-chloropyridine, and 5-bromo-2-chloropyridine.

[0031] According to a specific embodiment of the present invention, TiCl x The molar ratio to the organic base is 1:1 to 1.5.

[0032] Beneficial effects:

[0033] The present invention adopts the above technical scheme, selects a specific reducing agent catalyst system and controls the ratio of the reducing agent catalyst system to the reactant and the metal M at the same time, and simultaneously adopts a reflux reaction to activate the reducing agent catalyst system, so that the activity is higher, the reaction time is shortened, and a higher reaction efficiency and product selectivity are achieved. The preparation method of the high-performance fuel cage hydrocarbon compound BADH of the present invention is simple in process and short in reaction time. The selectivity of the target product is greater than 93%, the yield can reach 92%, and the product purity is above 99.5%, which has a high application prospect. DETAILED DESCRIPTION

[0034] The following further exemplifies the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention belong to the scope of protection of the present invention. The specific process parameters and the like in the following examples are only examples in a suitable range, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific values ​​​​exemplified below.

[0035] The present invention is further described in detail by way of examples. Unless otherwise specified, the raw materials used in the examples can be obtained through commercial sources.

[0036] Example 1

[0037] The caged hydrocarbon compound BADH was prepared by the following steps:

[0038] In a three-necked glass reactor, add 5.0g of zinc powder and 50mL of tetrahydrofuran, slowly drop 6.85g of TiCl4 at 0℃ under nitrogen atmosphere, slowly warm to room temperature after the addition, reflux at 85℃ for 1.5h, then cool to 0℃ again, drop 2.86g of pyridine reagent, then drop 5.0g of adamantane ketone and tetrahydrofuran (60ml) solution, then reflux at 85℃ for 7h. After the reaction is completed, add 100mL of 10% sodium carbonate solution, then extract with dichloromethane (60ml×3), dry the organic phase with anhydrous sodium sulfate, and then remove the solvent in vacuum to obtain a crude product. Recrystallize the crude product with n-hexane under vacuum to obtain a high-purity target product. Use gas chromatography-mass spectrometry to analyze the reaction solution, qualitatively characterize the product, and calculate the reaction conversion rate and product selectivity. The product selectivity, yield and purity are listed in Table 1. The caged hydrocarbon compound obtained by the reaction is adamantene dimer (BADH), and the physical and chemical properties are shown in Table 2 below.

[0039] Example 2

[0040] The caged hydrocarbon compound BADH was prepared by the method of Example 1, except that the amount of zinc powder used was 7.12 g, the amount of TiCl4 used was 9.42 g, and the amount of pyridine reagent used was 4.72 g. The product selectivity, yield and purity are listed in Table 1.

[0041] Example 3

[0042] The caged hydrocarbon compound BADH was prepared by the method of Example 1, except that the metal used was 2.13 g of sodium, 7.7 g of TiCl4, and 3.22 g of pyridine reagent. The product selectivity, yield and purity are listed in Table 1.

[0043] Example 4

[0044] The caged hydrocarbon compound BADH was prepared by the method of Example 1, except that the reflux temperature was 80° C. The product selectivity, yield and purity are listed in Table 1.

[0045] Comparative Example 1

[0046] The caged hydrocarbon compound BADH was prepared by the method of Example 1, except that after the dropwise addition of TiCl4, no reflux reaction was performed, and the subsequent experimental operation was directly performed. The product selectivity, yield and purity are listed in Table 1.

[0047] Comparative Example 2

[0048] The caged hydrocarbon compound BADH was prepared by the method of Example 1, except that the amount of zinc powder used was 8.4 g, the amount of TiCl4 used was 7.0 g, and the amount of pyridine used was 3.22 g. The product selectivity, yield and purity are listed in Table 1.

[0049] Comparative Example 3

[0050] The caged hydrocarbon compound BADH was prepared by the method of Example 1, except that the amount of zinc powder used was 10.83 g, the amount of TiCl4 used was 15.73 g, and the amount of pyridine used was 6.55 g. The product selectivity, yield and purity are listed in Table 1.

[0051] Comparative Example 4

[0052] The caged hydrocarbon compound BADH was prepared by the method of Example 1, except that the crude product was post-treated by column chromatography and the mobile phase was n-hexane. The product selectivity, yield and purity are listed in Table 1.

[0053] Table 1

[0054]

[0055] According to the data in Table 1, TiCl x The / M reducing agent system needs to be refluxed at 80-90°C for 0.5-3h to produce more active low-titanium species, which can then catalyze the McMurry coupling reaction of adamantane ketone, greatly improving the catalytic efficiency and product yield. x TiCl / M reducing agent system x The molar ratio of TiCl to the reactant is 1 to 2.0:1, and x When the molar ratio of BADH to metal is 1:1.5 to 3, the reaction time can be further shortened, and the product selectivity and yield can be improved. The crude product was purified by conventional column chromatography, and the purity of BADH was 98.2%, which was longer than the purification method of recrystallization under vacuum conditions, and the product purity was at least 1.3% lower.

[0056] Table 2

[0057]

[0058] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0059] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0060] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing a caged hydrocarbon compound, characterized in that: Adamantane ketone was used as the starting material, and TiCl x / M reducing agent system and organic base as catalyst, in an inert atmosphere, allowing adamantane ketone to undergo McMurry coupling reaction in a solvent to obtain the caged hydrocarbon compound; Before the reaction, TiCl x / M reducing agent system for reflux reaction; The TiCl x / M reducing agent system is TiCl x / Zn,TiCl x / Zn-Cu,TiCl x / Zn-Ag,TiCl x / Fe,TiCl x / Fe-Cu,TiCl x / Mg, TiCl x / K, TiCl x / Na, TiCl x / Li one or more; x is 3 or 4, preferably 4; The caged hydrocarbon compound is adamantane olefin dimer BADH.

2. The preparation method according to claim 1, characterized in that: The reflux reaction is carried out at 80-90° C. for 0.5-3 h, preferably 1-2.5 h.

3. The preparation method according to claim 1, characterized in that: TiCl x TiCl / M reducing agent system x The molar ratio of the reactant adamantanone is 1 to 2.0:1, preferably 1.1 to 2.0:1, and more preferably 1.1 to 1.5:

1.

4. The preparation method according to claim 1, characterized in that: TiCl x TiCl / M reducing agent system x The molar ratio of the metal M is 1:1.5 to 3, preferably 1:2.1 to 3, and more preferably 1:2.1 to 2.

5.

5. The preparation method according to claim 1, characterized in that: The following steps are involved: (1) Add metal M powder and solvent into the reactor, and slowly add TiCl in an inert atmosphere at -20 to 0°C. x ; (2) Titanium reagent TiCl x After the addition is completed, slowly warm to room temperature and reflux at 80-90°C for 0.5-3h; (3) cooling again to below 0°C, adding dropwise an organic base reagent, and then adding dropwise a mixed solution of adamantane ketone and a solvent, and reflux at 80 to 90°C for 5 to 10 hours; (4) Post-treating the reaction solution to obtain adamantane olefin dimer BADH.

6. The preparation method according to claim 5, characterized in that: The post-processing comprises the following steps: (1) obtaining a crude product by extraction; (2) Recrystallizing the crude product under vacuum conditions to obtain a high-purity target product; wherein the solvent used for recrystallization is one or more of petroleum ether, n-hexane, and methylcyclohexane.

7. The preparation method according to claim 6, characterized in that: The extraction step comprises: adding sodium carbonate or sodium bicarbonate solution to the reaction solution, then extracting with dichloromethane as an extractant, drying the obtained organic phase with anhydrous sodium sulfate, and then removing the solvent in vacuo to obtain the crude product; preferably, the concentration of the sodium carbonate or sodium bicarbonate solution is 5-20wt%, more preferably 10wt%.

8. The preparation method according to claim 5, characterized in that: The solvent in step (1) or step (3) is one or more of tetrahydrofuran, 1,4-dioxane, and ethylene glycol dimethyl ether.

9. The preparation method according to claim 5, characterized in that: The ratio of the reactant adamantanone to the solvent is 1:10-1:35 (g / mL).

10. The preparation method according to claim 5, characterized in that: The organic base is one or more of pyridine, 2-chloropyridine, 2-bromopyridine, 2-fluoropyridine, 2,4-dichloropyridine, 2,6-dichloropyridine, 1-bromo-2-chloropyridine, and 5-bromo-2-chloropyridine.

Images