Preparation method of carbon-based tungsten nanocatalytic material for catalytic oxidation of ring-opening of 1,2,3,4-tetrahydroquinoline compounds

Abstract

The present application relates to the preparation of catalytic material and organic synthesis technical field, specifically to a kind of preparation method of carbon-based tungsten nanometer catalytic material for catalyzing the ring-opening of 1,2,3,4-tetrahydroquinoline compound, deionized water is added to the mixture of nitrogen-containing polymer and ammonium tungstate pentahydrate and is fully stirred and dissolved;Water is removed by vacuum distillation process at a certain temperature to obtain the corresponding complex solid material and carry out nitrogen flow protection controllable programmed temperature rising pyrolysis, and then controllable cooling to room temperature to obtain carbon-based tungsten nanometer catalytic material;The prepared catalytic material is used as catalyst, 1,2,3,4-tetrahydroquinoline compound is used as reaction substrate, methanol is used as solvent, hydrogen peroxide is used as oxidant, argon is purged for a certain time, then argon is used as protective atmosphere, and 2-nitrobenzene propionic acid methyl ester compound is prepared by one-step catalysis under certain reaction temperature conditions;After the reaction is completed for 10-24h, the mixture is concentrated by vacuum distillation, and the reaction product is quantitatively analyzed by GC-MS.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of preparation of catalytic materials and organic synthesis, in particular to a preparation method of carbon-based tungsten nanocatalytic material for catalytic oxidation ring-opening of 1,2,3,4-tetrahydroquinoline compounds. BACKGROUND

[0002] 2-nitrobenzene propionic acid methyl ester compounds are important pharmaceutical intermediates, which are usually used for the synthesis and preparation of glycogen phosphorylase inhibitors. In addition, due to the inhibition of microtubule protein polymerization, the compounds are also used for the research and development of high-efficiency anticancer drugs. Although the compounds have important role in drug synthesis and research, the corresponding preparation research is very limited. In many reported research cases in recent decades, the preparation of 2-nitrobenzene propionic acid methyl ester compounds is still based on several catalytic coupling reactions with low yield and complex steps. In particular, these coupling reactions have unavoidable disadvantages such as harsh reaction conditions, many by-products, acid-base reaction system, and large amount of catalysts (Helv. Chim. Acta, 1961, 44, 1736-1747; Synth. Commun., 1995, 25, 3067-3074; Tetrahedron Lett., 2001, 42, 6767-6769). Therefore, from the application of green chemistry and circular economy, it is necessary to construct a functional heterogeneous catalytic material, and to realize the simple, efficient and green preparation of 2-nitrobenzene propionic acid methyl ester compounds by catalytic oxidation ring-opening of 1,2,3,4-tetrahydroquinoline compounds.

[0003] In recent years, there have been many reports on the catalytic hydrogenation ring-opening of 1,2,3,4-tetrahydroquinoline compounds, because the C-N bond in 1,2,3,4-tetrahydroquinoline compounds usually has a high bond energy, and therefore the C-N bond ring-opening of such compounds is usually achieved by catalytic hydrogenation denitrification strategy (J. Catal., 2012, 295, 155-168; Nat. Commun., 2017, 8, 1-8; Fuel, 2019, 236, 55-64). However, the corresponding reports on the catalytic oxidation ring-opening of 1,2,3,4-tetrahydroquinoline compounds are relatively rare. This is because 1,2,3,4-tetrahydroquinoline compounds are more likely to undergo dehydrogenation under catalytic oxidation conditions to generate more stable quinoline compounds (J. Am. Chem. Soc., 2015, 137, 10652-10658; Chem. Sci., 2019, 10, 5345-5352). In fact, a case of one-pot preparation of 2-nitrobenzene propionic acid methyl ester by catalytic oxidation of 1,2,3,4-tetrahydroquinoline has been reported (Org. Biomol. Chem., 2019, 17, 4970-4974). Its efficient conversion process and mild catalytic reaction conditions reflect the development concept of green chemistry. However, in this reported case, the catalytic material still has a difficult-to-overcome drawback in use: the catalytic material has poor stability and is deactivated and partially lost after each use, and the catalytic material after separation must be subjected to a relatively complex activity recovery process to continue to be used (from the perspective of catalysis, the catalytic material involved in this case cannot be recognized as a catalyst). Therefore, the practical application and development of the catalytic material are limited. SUMMARY

[0004] To solve the above technical problems, the present application provides a preparation method of a carbon-based tungsten nanocatalytic material for catalytic oxidation ring-opening of 1,2,3,4-tetrahydroquinoline compounds. The catalytic material directly catalyzes the oxidation ring-opening esterification of 1,2,3,4-tetrahydroquinoline compounds in a methanol solvent system through the active structure formed by the interaction of the internal tungsten site and nitrogen-doped carbon, to achieve simple, efficient, green and low-cost catalytic preparation of 2-nitrobenzene propionic acid methyl ester compounds.

[0005] To achieve the above purpose, the present application provides the following technical solutions:

[0006] A preparation method of a carbon-based tungsten nanocatalytic material for catalytic oxidation ring-opening of 1,2,3,4-tetrahydroquinoline compounds, characterized in that it comprises the following steps:

[0007] Step one, add a certain amount of deionized water to the mixture of nitrogen-containing polymer and ammonium tungsten oxide pentahydrate mixed in a certain mass ratio and fully stir to dissolve;

[0008] Step two, after fully dissolving, remove water by vacuum distillation at a certain temperature to obtain the corresponding complex solid material, and then perform a controllable programmed temperature increase pyrolysis under nitrogen flow protection, and then controllable cooling to room temperature to obtain carbon-based tungsten nanocatalytic material;

[0009] Step three, using the prepared catalytic material as a catalyst, 1,2,3,4-tetrahydroquinoline compounds as a reaction substrate, methanol as a solvent, hydrogen peroxide as an oxidant, purging with argon for a certain time, then continuing to use argon as a protective atmosphere, one-step catalytic preparation of 2-nitrobenzene propionic acid methyl ester compounds under certain reaction temperature conditions;

[0010] Step four, after the reaction is completed for 10-24h, the mixture is concentrated by vacuum distillation, and the reaction product is quantitatively analyzed by GC-MS (Agilent GC-MS-hp5890) (external standard quantitative method).

[0011] As preferred, in step one, the nitrogen-containing polymer is one of polyvinylpyrrolidone, polyacrylamide, polyisopropyl acrylamide, and poly-N-vinyl caprolactam.

[0012] As preferred, in step one, the mass ratio of nitrogen-containing polymer: ammonium tungsten oxide pentahydrate is 1:1.5-8.

[0013] As preferred, in step one, the mass ratio of nitrogen-containing polymer: deionized water added is 1:50-90.

[0014] As preferred, in step two, the vacuum distillation temperature for removing water to obtain the corresponding complex solid material by vacuum distillation is 70-90°C.

[0015] As preferred, in step two, the controllable high-temperature pyrolysis is performed in a tube furnace, with a final temperature range of 600-900°C, and a holding time of 1-3h after reaching the final temperature.

[0016] As preferred, in step two, the temperature increase step of controllable high-temperature pyrolysis is 3-8°C / min.

[0017] As preferred, in step two, after the high-temperature pyrolysis process is completed, the controllable cooling step is 5-10°C / min to room temperature.

[0018] As preferred, in step three, the order of feeding and operating in the pressure reaction tube is: adding carbon-based tungsten nanocatalytic material, adding 1,2,3,4-tetrahydroquinoline compound, adding solvent methanol, purging the pressure tube with argon (purging time = 2 min ~ 30 min), adding hydrogen peroxide solution before the end of purging, and sealing the pressure tube with a polytetrafluoroethylene screw cap.

[0019] As preferred, in step three, the amount of carbon-based tungsten nanocatalytic material for catalytic reaction added in the pressure reaction tube is 30 ~ 80 mg / mmol of 1,2,3,4-tetrahydroquinoline compound.

[0020] As preferred, in step three, the volume of solvent methanol added in the pressure reaction tube is 1 ~ 5 ml / mmol of 1,2,3,4-tetrahydroquinoline compound.

[0021] As preferred, in step three, the concentration of oxidant hydrogen peroxide solution added in the pressure reaction tube is 10 ~ 30 wt%; the amount of hydrogen peroxide is 7 ~ 15 mmol / mmol of 1,2,3,4-tetrahydroquinoline compound.

[0022] As preferred, in step three, the heating temperature of the catalytic reaction system is 50 ~ 80℃.

[0023] As preferred, in step three, the catalytic reaction time is 10 ~ 24 h.

[0024] As preferred, the reaction equation of the catalytic reaction is:

[0025]

[0026] The beneficial effects of the present application are: 1. The preparation method of the carbon-based tungsten nanocatalytic material for catalyzing the ring-opening of 1,2,3,4-tetrahydroquinoline compound, which uses nitrogen-containing polymer as carbon precursor material and ammonium tungstate pentahydrate as active center precursor material, can obtain the corresponding carbon-based tungsten nanocatalytic material through simple mixing and controllable high-temperature pyrolysis. At the same time, using this kind of catalytic material as catalyst and hydrogen peroxide as oxidant, the direct catalytic oxidation of 1,2,3,4-tetrahydroquinoline compound in a methanol solvent system realizes the low-cost one-pot preparation of 2-nitrobenzene propionic acid methyl ester compound. Among them, this kind of catalytic material is simple to prepare, stable in performance, low in cost and controllable in process. Therefore, the present application has obvious innovation and potential value for development of fine chemical industry. In particular, this kind of catalytic material has good catalytic activity and stability, and can be directly reused through simple separation without the need for further activity recovery process. Through 30 cycles of catalytic experiments, the activity loss of the catalytic material is not more than 10%. It has obvious innovation and potential industrial development value.

[0027] 2. The application relates to a preparation method of a carbon-based tungsten nanocatalytic material for catalytically oxidizing the ring opening of 1,2,3,4-tetrahydroquinoline compounds, wherein the raw material cost is low, the catalyst preparation process is simple, the reaction can be scaled up in proportion to complete the preparation of related products in a gram level, the reaction condition is mild, the catalytic performance is stable, the atomic economy is high, the overall reaction is sustainable, the catalytic material can be reused through simple separation, and an activity recovery treatment is not needed. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the embodiments of the application. Apparently, the described embodiments are only part of the embodiments of the application, instead of all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0029] Embodiment 1

[0030] In a 250ml flask, polyvinylpyrrolidone and ammonium tungstate pentahydrate (the total mass is 2.5g) with a mass ratio of 1:1.5 and 70ml of deionized water are respectively added, and stirring and dissolution are performed. Water is removed by distillation under reduced pressure at 80 DEG C to obtain a corresponding complex solid material. The corundum boat containing the complex solid material is transferred to a tube furnace, nitrogen is used as a protective gas, high-temperature pyrolysis is performed at a controllable temperature (the temperature rising rate is controlled to be 4 DEG C / min until the temperature reaches 900 DEG C, and the temperature is kept at 900 DEG C for 1h), then the temperature is reduced to room temperature at a rate of 8 DEG C / min, and a carbon-based tungsten nanocatalytic material is obtained. Subsequently, 0.5mmol of 1,2,3,4-tetrahydroquinoline, 20mg of the prepared carbon-based tungsten nanocatalytic material, 2ml of methanol and 5mmol of H2O2 are respectively added to a 38ml pressure tube, the tube opening is sealed with a polytetrafluoroethylene screw cap after being purged with argon for 5min, and then stirring reaction is performed at 65 DEG C for 18h. Subsequently, the obtained mixture is concentrated by distillation under reduced pressure, and quantitative analysis (external standard quantitative method) of the reaction product is performed by using GC-MS (Agilent GC-MS-hp5890), and the yield of the target product 2-nitrobenzene propionic acid is 72%.

[0031] Embodiment 2

[0032] In a 250 ml flask, 1 : 1.5 mass ratio of polyvinylpyrrolidone and tungsten ammonium oxide pentahydrate (total mass of 2.5 g) and 70 mL of deionized water were added, and fully stirred and dissolved. Water was removed by distillation under reduced pressure at 80°C to obtain the corresponding complex solid material. The corundum boat containing the complex solid material was transferred to a tube furnace, and pyrolysis was carried out at a controlled temperature (the temperature was raised at a rate of 4°C / min until the temperature reached 900°C, and maintained at this temperature for 1 h) under the protection of nitrogen gas. After that, the temperature was lowered to room temperature at a rate of 8°C / min, and a carbon-based tungsten nanocatalytic material was obtained. Subsequently, 0.5 mmol of 6-methyl-1,2,3,4-tetrahydroquinoline, 20 mg of the prepared carbon-based tungsten nanocatalytic material, 2 mL of methanol, and 5 mmol of H2O2 were added to a 38 mL pressure tube, which was purged with argon for 5 min, and then sealed with a polytetrafluoroethylene screw cap. Subsequently, the reaction was stirred at 65°C for 18 h. Subsequently, the obtained mixture was concentrated by distillation under reduced pressure, and the reaction product was quantitatively analyzed by GC-MS (Agilent GC-MS-hp5890) (external standard method), and the yield of the target product 5-methyl-2-nitrobenzene propionic acid methyl ester was 70%.

[0033] Example 3

[0034] In a 250 ml flask, 1 : 1.5 mass ratio of polyvinylpyrrolidone and tungsten ammonium oxide pentahydrate (total mass of 2.5 g) and 70 mL of deionized water were added, and fully stirred and dissolved. Water was removed by distillation under reduced pressure at 80°C to obtain the corresponding complex solid material. The corundum boat containing the complex solid material was transferred to a tube furnace, and pyrolysis was carried out at a controlled temperature (the temperature was raised at a rate of 4°C / min until the temperature reached 900°C, and maintained at this temperature for 1 h) under the protection of nitrogen gas. After that, the temperature was lowered to room temperature at a rate of 8°C / min, and a carbon-based tungsten nanocatalytic material was obtained. Subsequently, 0.5 mmol of 6-methyl-1,2,3,4-tetrahydroquinoline, 20 mg of the prepared carbon-based tungsten nanocatalytic material, 2 mL of methanol, and 5 mmol of H2O2 were added to a 38 mL pressure tube, which was purged with argon for 5 min, and then sealed with a polytetrafluoroethylene screw cap. Subsequently, the reaction was stirred at 65°C for 18 h. Subsequently, the obtained mixture was concentrated by distillation under reduced pressure, and the reaction product was quantitatively analyzed by GC-MS (Agilent GC-MS-hp5890) (external standard method), and the yield of the target product 5-methyl-2-nitrobenzene propionic acid methyl ester was 70%.

[0035] Example 4

[0036] In a 250 ml flask, polyvinylpyrrolidone and ammonium tungstate pentahydrate (total mass of 2.5 g) in a mass ratio of 1:1.5 and 70 mL of deionized water were added respectively, and fully stirred and dissolved. Water was removed by distillation under reduced pressure at 80°C to obtain the corresponding complex solid material. The corundum boat containing the complex solid material was transferred to a tube furnace, and high-temperature pyrolysis was carried out under a controlled temperature (the temperature was raised to 900°C at a rate of 4°C / min, and maintained at this temperature for 1 h) with nitrogen as the protective gas. Then, the temperature was lowered to room temperature at a rate of 8°C / min. A carbon-based tungsten nanocatalytic material was obtained. Subsequently, 0.5 mmol of 5-bromo-1,2,3,4-tetrahydroquinoline, 20 mg of the prepared carbon-based tungsten nanocatalytic material, 2 mL of methanol, and 5 mmol of H2O2 were added to a 38 mL pressure tube, which was purged with argon for 5 min, and then sealed with a polytetrafluoroethylene screw cap. Subsequently, the reaction was stirred at 65°C for 18 h. Then, the obtained mixture was concentrated by distillation under reduced pressure, and the reaction product was quantitatively analyzed by GC-MS (Agilent GC-MS-hp5890) (external standard method), and the yield of the target product 2-nitro-6-bromophenylpropionic acid methyl ester was 70%.

[0037] Example 5

[0038] In a 250 ml flask, polyvinylpyrrolidone and ammonium tungstate pentahydrate (total mass of 2.5 g) in a mass ratio of 1:1.5 and 70 mL of deionized water were added respectively, and fully stirred and dissolved. Water was removed by distillation under reduced pressure at 80°C to obtain the corresponding complex solid material. The corundum boat containing the complex solid material was transferred to a tube furnace, and high-temperature pyrolysis was carried out under a controlled temperature (the temperature was raised to 900°C at a rate of 4°C / min, and maintained at this temperature for 1 h) with nitrogen as the protective gas. Then, the temperature was lowered to room temperature at a rate of 8°C / min. A carbon-based tungsten nanocatalytic material was obtained. Subsequently, 0.5 mmol of 5-bromo-1,2,3,4-tetrahydroquinoline, 20 mg of the prepared carbon-based tungsten nanocatalytic material, 2 mL of methanol, and 5 mmol of H2O2 were added to a 38 mL pressure tube, which was purged with argon for 5 min, and then sealed with a polytetrafluoroethylene screw cap. Subsequently, the reaction was stirred at 65°C for 18 h. Then, the obtained mixture was concentrated by distillation under reduced pressure, and the reaction product was quantitatively analyzed by GC-MS (Agilent GC-MS-hp5890) (external standard method), and the yield of the target product 2-nitro-6-bromophenylpropionic acid methyl ester was 70%.

[0039] Example 6

[0040] In a 250 mL flask, polyvinylpyrrolidone and ammonium tungstate pentahydrate (total mass 2.5 g) with a mass ratio of 1:1.5 and 70 mL of deionized water were added respectively, and stirred to dissolve. The water was removed by distillation under reduced pressure at 80°C to obtain the corresponding complex solid material. The corundum boat containing the complex solid material was transferred to a tube furnace, and high temperature pyrolysis was carried out under the protection of nitrogen gas at a controllable temperature (the temperature was raised at a rate of 4°C / min until the temperature reached 900°C, and then kept at this temperature for 1 h), and then cooled to room temperature at a rate of 8°C / min. Carbon-based tungsten nanocatalytic material was obtained. Subsequently, 10 mmol of 1,2,3,4-tetrahydroquinoline, 400 mg of the prepared carbon-based tungsten nanocatalytic material, 40 mL of methanol, and 100 mmol of H2O2 were added to a 250 mL pressure jacket / tube, which was purged with argon for 25 min, and then sealed with a polytetrafluoroethylene screw cap. Subsequently, the reaction was stirred at 65°C for 18 h. Subsequently, the obtained mixture was concentrated by distillation under reduced pressure, and the reaction product was quantitatively analyzed by GC-MS (Agilent GC-MS-hp5890) (external standard method). The yield of the target product 2-nitrobenzene propionic acid was 67%.

[0041] The present application is not limited to the above-mentioned specific embodiments, and the above-mentioned specific embodiments are only illustrative and not restrictive. Those skilled in the art can make many forms under the inspiration of the present application without departing from the scope of the present application and the scope of protection of the claims, and all of them belong to the protection of the present application.

Claims

1. A method for preparing carbon-based tungsten nanocatalytic material for catalytic oxidation of ring-opening of 1,2,3,4-tetrahydroquinoline compounds, characterized in that, The method comprises the following steps: Step one, mixing nitrogen-containing polymer and ammonium tungstate pentahydrate according to a mass ratio of 1:1.5-8, adding deionized water to the obtained mixture and fully stirring and dissolving, wherein the mass ratio of the nitrogen-containing polymer to the added deionized water is 1:50-90; Step two, after fully dissolving, removing water through a 70-90 ℃ reduced-pressure distillation process to obtain a corresponding complex solid material, and performing a controllable programmed temperature pyrolysis on the complex solid material under nitrogen flow protection, with a terminal temperature of 600-900 ℃, and then controllably cooling to room temperature to obtain a carbon-based tungsten nanocatalytic material; Step three, using the prepared catalytic material as a catalyst, performing a one-step ring-opening esterification reaction on a 1,2,3,4-tetrahydroquinoline compound in methanol as a solvent and hydrogen peroxide as an oxidant under argon protection at 50-80 ℃; the catalytic material can be directly reused after a simple separation after the reaction, without the need for an activity recovery treatment before reuse.

2. The preparation method of carbon-based tungsten nanocatalytic material for catalytic oxidation of 1,2,3,4-tetrahydroquinoline ring-opening according to claim 1, characterized in that, In step one, the nitrogen-containing polymer is one of polyvinylpyrrolidone, polyacrylamide, polyisopropyl acrylamide and poly-N-vinyl caprolactam.

3. The preparation method of the carbon-based tungsten nanocatalytic material for catalytically oxidizing the ring-opening of 1,2,3,4-tetrahydroquinoline compounds according to claim 1, characterized in that, In step two, the programmed pyrolysis under nitrogen protection is performed in a tube furnace, with a temperature rising rate of 3-8 ℃ / min to a terminal temperature of 600-900 ℃ and a holding time of 1-3 h, and then a temperature falling rate of 5-10 ℃ / min to room temperature.

4. The preparation method of the carbon-based tungsten nanocatalytic material for catalytically oxidizing the ring-opening of 1,2,3,4-tetrahydroquinoline compounds according to claim 1, characterized in that, In step three, the feeding and operation sequence in the pressure reaction tube is as follows: adding the carbon-based tungsten nanocatalytic material, adding the 1,2,3,4-tetrahydroquinoline compound, adding the solvent methanol, purging the pressure tube with argon, a purging time of 2 min-30 min, adding a hydrogen peroxide solution before the end of purging and sealing the pressure tube with a polytetrafluoroethylene screw cap.

5. The method for preparing carbon-based tungsten nanocatalytic material for catalytic oxidation of 1,2,3,4-tetrahydroquinoline ring-opening according to claim 1, characterized in that, In step three, the amount of the carbon-based tungsten nanocatalytic material added in the pressure reaction tube for catalytic reaction is 30-80 mg / mmol of the 1,2,3,4-tetrahydroquinoline compound.

6. The method for preparing carbon-based tungsten nanocatalytic material for catalytic oxidation of 1,2,3,4-tetrahydroquinoline ring-opening according to claim 1, characterized in that, In step three, the volume of the solvent methanol added in the pressure reaction tube is 1-5 ml / mmol of the 1,2,3,4-tetrahydroquinoline compound; the concentration of the oxidant hydrogen peroxide solution added in the pressure reaction tube is 10-30 wt%; the amount of the hydrogen peroxide used is 7-15 mmol / mmol of the 1,2,3,4-tetrahydroquinoline compound; and the catalytic reaction time is 10-24 h.

7. The method for preparing carbon-based tungsten nanocatalytic material for catalytic oxidation of 1,2,3,4-tetrahydroquinoline ring-opening according to claim 1, characterized in that, The reaction equation of the catalytic reaction is as follows:

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