A catalyst for preparing aminophenylacetylene by hydrogenation of nitrophenylacetylene

Abstract

The application relates to a catalyst for selectively hydrogenating nitrophenylacetylene to prepare aminophenylacetylene. The Fe2O3-CeO2 / TiO2 catalyst is used, the solvent is anhydrous ethanol, the hydrogen source is hydrazine hydrate, and the nitrophenylacetylene is catalytically hydrogenated to prepare aminophenylacetylene at 80-150 DEG C. The catalyst can realize efficient hydrogenation of the nitro group in the nitrophenylacetylene, the selectivity of the aminophenylacetylene can reach 94.8% when the nitrophenylacetylene is completely converted, the selectivity of the aminophenylacetylene is basically unchanged when the reaction time is continuously prolonged, and there is no accumulation of harmful intermediates such as phenylhydroxylamine in the reaction process.

Description

TECHNICAL FIELD

[0001] The present application relates to a catalyst for the catalytic hydrogenation of nitrophenylacetylene to prepare aminophenylacetylene. Specifically, it relates to a method for the selective hydrogenation of nitrophenylacetylene to prepare aminophenylacetylene using Fe2O3-CeO2 / TiO2 as a catalyst in a green solvent, anhydrous ethanol, and using hydrazine hydrate as a hydrogen source. BACKGROUND

[0002] Aminophenylacetylene is an important precursor of pharmaceutical active compounds and acetylenic end group polymers, and is also an important intermediate for the synthesis of the effective anticancer drug, erlotinib hydrochloride.

[0003] Catalytic hydrogenation of nitrophenylacetylene is a relatively clean process for preparing aminophenylacetylene. Nitrophenylacetylene contains two easily reduced groups, nitro and acetylene. A catalyst with high activity for hydrogenation of nitro groups and inertness for hydrogenation of acetylene groups is the key to improving the yield of aminophenylacetylene.

[0004] The research progress of noble metal catalysts for the catalytic hydrogenation of nitrophenylacetylene to prepare aminophenylacetylene is summarized as follows. Using 0.2wt%Pt / TiO2 as a catalyst and toluene as a solvent, 4-nitrophenylacetylene was catalytically hydrogenated at 6barH2 and 313K for 5.6h, with a conversion rate of 98.9% and a selectivity of 90.1% for 4-aminophenylacetylene (Corma, et al., J. Am. Chem. Soc., 2008). In the presence of CO and H2, using toluene-water as the reaction medium, 0.25%Pt / α-MoC was used to catalyze the hydrogenation of 4-nitrophenylacetylene, which was reacted for 4h, with a conversion rate of 100% and a selectivity of 99.9% for 4-aminophenylacetylene (Lili Lin, et al., Nat. Nanotech., 2019). PdCd 1.13 Catalytic hydrogenation of 4-nitrophenylacetylene was carried out using HCOONH4 as a hydrogen source in DMF at 60℃ for 3h, with complete conversion of the reactant and a selectivity of 92% for 4-aminophenylacetylene (Yonggang Feng, et al., J. Am. Chem. Soc., 2020). Using ammonia borane as a hydrogen source, PtZn / HNCNT was used to catalyze the hydrogenation of 4-nitrophenylacetylene in a mixture of ethanol and water at 40℃ for 4h, with a conversion rate of >99% and a selectivity of 99% for 4-aminophenylacetylene (Aijuan Han, et al., Nat. Commun., 2019). Using Pt-Zn / SnO2-Sb2O3 as a catalyst, 4-nitrophenylacetylene was catalytically hydrogenated in ethanol at 50℃ and 4MPaH2 for 20min, with a conversion rate of 100% and a selectivity of 87.9% for 4-aminophenylacetylene (CN 107216255 B).

[0005] The cost of noble metal catalysts is high. The progress of using non-noble metal catalysts to prepare aminophenylacetylene by hydrogenation of nitrophenylacetylene is as follows. CoS x is used as a catalyst, 3-nitrophenylacetylene is reacted at 108℃ under 1000psig H2pressure for 0.75h, and the yield of 3-aminophenylacetylene is 86% (Anatoli Onopchenko, et al., J. Org. Chem., 1979). The reaction process produces sulfur-containing by-products, and there are disadvantages such as difficult reuse of solvents and serious environmental pollution. 3wt% Co / C prepared by high-temperature pyrolysis catalyzes the hydrogenation of 4-nitrophenylacetylene in tetrahydrofuran, and the yield of 4-aminophenylacetylene is 88% under the conditions of 110℃, 50bar H2pressure and 4h (Felix A. Westerhaus, et al., Nat. Chem., 2013). Fe(OAc)2, 1,10-phenanthroline and carbon powder are mixed, and nitrogen-doped Fe2O3-N / C catalyst prepared by high-temperature pyrolysis at 800℃ catalyzes the reaction of 4-nitrophenylacetylene in tetrahydrofuran with hydrazine hydrate as a hydrogen source at 100℃ for 10h, and the reaction is completely converted, and the selectivity of 4-aminophenylacetylene is 96% (Rajenahally V. Jagadeesh, et al., Chem. Commun., 2011); in addition, 60mg Fe2O3-N / C catalyzes the reaction of 0.5mmol 4-nitrophenylacetylene in 1:1 water-tetrahydrofuran solvent under the conditions of 105℃, 50bar H2pressure and 26h, and the yield of 4-aminophenylacetylene is 75% (Rajenahally V. Jagadeesh, et al., Science, 2013).

[0006] The use of non-noble metal catalysts to catalyze the hydrogenation of nitrophenylacetylene can significantly reduce the cost of catalyst preparation. However, there are still the following disadvantages: (1) the reaction is carried out in harmful and volatile organic solvents such as toluene, which pollutes the environment; (2) the activity of the catalyst is low, and the reaction time is too long; (3) the preparation conditions of the catalyst are harsh. SUMMARY

[0007] The present application relates to a method for selectively hydrogenating nitrophenylacetylene to prepare aminophenylacetylene using Fe2O3-CeO2 / TiO2 as a catalyst in green solvent ethanol with hydrazine hydrate as a hydrogen source.

[0008] The technical scheme of the present application is: anhydrous ethanol, nitrophenylacetylene, catalyst Fe2O3-CeO2 / TiO2 and 80% hydrazine hydrate solution are added into a reactor, the mass ratio of anhydrous ethanol to nitrophenylacetylene is (20-120):1, the mass ratio of nitrophenylacetylene to catalyst is (1-20):1, the molar ratio of N2H4·H2O to nitrophenylacetylene is (1.5-4):1, the reactor is tightened, high-purity nitrogen is blown for 5 minutes at room temperature to remove air in the reactor, then the reactor is heated to 80-150 DEG C, and after preheating for 20 minutes, stirring is started, and the reaction is continued until the conversion rate is close to or reaches 100%.

[0009] The nitrophenylacetylene is 2-nitrophenylacetylene, 3-nitrophenylacetylene or 4-nitrophenylacetylene.

[0010] The Fe2O3-CeO2 / TiO2 catalyst is prepared by the following method: a mixed solution of iron and cerium nitrate in a certain ratio is impregnated on TiO2 powder by using an equal-volume impregnation method. After the sample is dried at 120 DEG C for 12 hours, it is ground, sieved, and calcined in a muffle furnace in an air atmosphere at 200-500 DEG C for 2-5 hours to obtain the catalyst Fe2O3-CeO2 / TiO2, wherein the mass content of Fe2O3 is 8%-15%, and the molar ratio of Fe to Ce is (1-20):1.

[0011] The present application has the following advantages:

[0012] (1) Anhydrous ethanol is used as the solvent, which avoids pollution of the environment caused by harmful solvents such as toluene and tetrahydrofuran.

[0013] (2) The catalyst has high activity and high selectivity for hydrogenation of the nitro group in nitrophenylacetylene, and the selectivity of aminophenylacetylene can be as high as 94.8%. The catalyst has almost no catalytic activity for hydrogenation of aminophenylacetylene, so the selectivity of aminophenylacetylene does not decrease substantially even if the reaction time is extended after the reactants are completely converted, which reduces the difficulty of controlling the reaction in large-scale production.

[0014] (3) The activity of Fe2O3-CeO2 / TiO2 is significantly higher than that of Fe2O3 / TiO2 without substantially changing the selectivity of the target product.

[0015] (4) There is no accumulation of harmful intermediates such as phenylhydroxylamine, nitroso compounds and azo compounds during the reaction.

[0016] In summary, using Fe2O3-CeO2 / TiO2 as the catalyst, hydrazine hydrate as the hydrogen source and anhydrous ethanol as the solvent, the nitrophenylacetylene is catalytically hydrogenated to prepare aminophenylacetylene, which is a green and environmentally friendly high-efficiency process. DETAILED DESCRIPTION

[0017] Example 1 Catalyst preparation and hydrogenation of 4-nitrophenylacetylene

[0018] A mixed solution of nitrates with iron and cerium content of 1.88 mol / L and 0.188 mol / L respectively was prepared. Iron and cerium were loaded on TiO2(P25) by equal-volume impregnation. After drying at 120°C for 12 h, the mixture was ground, sieved and calcined in a muffle furnace at 250°C for 3 h in air to obtain a 9.8 wt% Fe2O3-CeO2 / TiO2 catalyst (molar ratio of Fe to Ce was 10:1).

[0019] Into a 30 mL high-pressure reactor with a polytetrafluoroethylene liner, 10 mL of ethanol, 0.5 mmol of 4-nitrophenylacetylene, 80% hydrazine hydrate solution containing 0.9 mmol of N2H4·H2O and 0.05 g of the catalyst were added. The reactor was tightly closed, purged with high-purity nitrogen for 5 min to remove air, preheated in an oil bath at 120°C for 20 min, and then the stirring was started. The reaction time was 10 min and 30 min, respectively. The reaction products were analyzed by gas chromatography. The conversion of 4-nitrophenylacetylene was 100% and the selectivity of 4-aminophenylacetylene was 94.5% after 10 min of reaction. The conversion of 4-nitrophenylacetylene was 100% and the selectivity of 4-aminophenylacetylene was 94.4% after 30 min of reaction.

[0020] Example 2 Hydrogenation of 4-nitrophenylacetylene

[0021] The catalyst was prepared as in Example 1.

[0022] The catalyst dosage was 0.02 g, the reaction temperature was 80°C, the reaction time was 5 min, and the other conditions were the same as in Example 1. The conversion of 4-nitrophenylacetylene was 54.7% and the selectivity of 4-aminophenylacetylene was 93.8%.

[0023] Comparative Example 1 Hydrogenation of 4-nitrophenylacetylene

[0024] A solution of iron nitrate was prepared. Fe(NO3)3 was loaded on TiO2(P25) by equal-volume impregnation. After drying at 120°C for 12 h, the mixture was ground, sieved and calcined in a muffle furnace at 300°C for 3 h in air to obtain a 9.8 wt% Fe2O3 / TiO2 catalyst.

[0025] 0.02 g of the catalyst was taken, the reaction time was 10 min, and the other conditions were the same as in Example 2. The conversion of 4-nitrophenylacetylene was 53.7% and the selectivity of 4-aminophenylacetylene was 92.7%.

[0026] Example 3 Hydrogenation of 4-nitrophenylacetylene

[0027] The catalyst was calcined in a muffle furnace in air atmosphere at 300°C for 3h, and the other preparation process and conditions were the same as those in Example 1.

[0028] The reaction kettle was charged with 10 mL of ethanol, 2 mmol of 4-nitrophenylacetylene, 80% hydrazine hydrate solution containing 3.63 mmol of N2H4-H2O, and 0.2 g of the catalyst, and the reaction time was 10 min, with the other conditions being the same as those in Example 1. The conversion of 4-nitrophenylacetylene was 100%, and the selectivity of 4-aminophenylacetylene was 87.6%.

[0029] Example 4 Hydrogenation of 4-nitrophenylacetylene

[0030] The catalyst was prepared under the conditions of Example 2.

[0031] The reaction kettle was charged with 10 mL of ethanol, 0.5 mmol of 4-nitrophenylacetylene, 80% hydrazine hydrate solution containing 1.22 mmol of N2H4-H2O, and 0.005 g of the catalyst, and the reaction temperature was 150°C, the reaction time was 45 min, and the other conditions were the same as those in Example 1. The conversion of 4-nitrophenylacetylene was 100%, and the selectivity of 4-aminophenylacetylene was 90.8%.

[0032] Example 5 Catalyst preparation and hydrogenation of 4-nitrophenylacetylene

[0033] A mixed nitrate solution containing 1.88 mol / L of iron and 1.88 mol / L of cerium was prepared, and iron and cerium were loaded on TiO2 (P25) by the equal-volume impregnation method. After drying at 120°C for 12 h, the mixture was ground, sieved, and calcined in a muffle furnace in air atmosphere at 450°C for 3 h to obtain a 9.0 wt% Fe2O3-CeO2 / TiO2 catalyst (the molar ratio of Fe to Ce was 1:1).

[0034] The reaction kettle was charged with 0.05 g of the catalyst and 1.52 mmol of N2H4-H2O in 80% hydrazine hydrate solution, and the reaction time was 15 min, with the other conditions being the same as those in Example 1. The conversion of 4-nitrophenylacetylene was 100%, and the selectivity of 4-aminophenylacetylene was 92.4%.

[0035] Example 6 Catalyst preparation and hydrogenation of 4-nitrophenylacetylene

[0036] A mixed nitrate solution containing 1.88 mol / L of iron and 0.09 mol / L of cerium was prepared, and iron and cerium were loaded on TiO2 (P25) by the equal-volume impregnation method. After drying at 120°C for 12 h, the mixture was ground, sieved, and calcined in a muffle furnace in air atmosphere at 300°C for 3 h to obtain a 10.3 wt% Fe2O3-CeO2 / TiO2 catalyst (the molar ratio of Fe to Ce was 20:1).

[0037] Example 1 0.05 g of the catalyst was used, the reaction temperature was 80 °C, the reaction time was 10 min, and the other conditions were the same as in Example 1. The conversion of 4-nitrophenylacetylene was 100%, and the selectivity of 4-aminophenylacetylene was 94.2%.

[0038] Example 7 Hydrogenation of 3-nitrophenylacetylene

[0039] The catalyst was prepared as in Example 3, and the amount used was 0.05 g. The reactant was 0.5 mmol of 3-nitrophenylacetylene. The reaction time was 30 min, and the other conditions were the same as in Example 1. The conversion of 3-nitrophenylacetylene was 100%, and the selectivity of 3-aminophenylacetylene was 94.8%.

[0040] Example 8 Hydrogenation of 2-nitrophenylacetylene

[0041] The reactant was 0.5 mmol of 2-nitrophenylacetylene, the reaction time was 10 min, and the catalyst and other conditions were the same as in Example 7. The conversion of 2-nitrophenylacetylene was 100%, and the selectivity of 2-aminophenylacetylene was 92.4%.

Claims

1. A catalyst for the hydrogenation of nitrophenylacetylene to aminophenylacetylene, characterized in that The Fe2O3-CeO2 / TiO2 catalyst is used, anhydrous ethanol is used as a solvent, and hydrazine hydrate is used as a hydrogen source to catalyze hydrogenation of nitrophenyl acetylene at 80-150 DEG C to prepare aminophenyl acetylene; The Fe2O3-CeO2 / TiO2 catalyst contains 8-15% of Fe2O3 by mass, and the molar ratio of Fe to Ce is (1-20):1; The nitrophenyl acetylene is 2-nitrophenyl acetylene, 3-nitrophenyl acetylene or 4-nitrophenyl acetylene; The nitrophenyl acetylene is hydrogenated to prepare aminophenyl acetylene, anhydrous ethanol, nitrophenyl acetylene, the catalyst Fe2O3-CeO2 / TiO2 and 80% hydrazine hydrate solution are added into a reactor, the mass ratio of the solvent to the nitrophenyl acetylene is (20-120):1, the mass ratio of the nitrophenyl acetylene to the catalyst is (1-20):1, the molar ratio of N2H4·H2O to the nitrophenyl acetylene is (1.5-4):1, the reactor is screwed tightly, high-purity nitrogen is used to purge the reactor at room temperature, then the reactor is heated to 80-150 DEG C, stirring is started after preheating for 20 min, the reaction is carried out until the conversion rate reaches 100%, and the reaction time is less than 60 min.

2. A catalyst for the hydrogenation of a nitrophenylacetylene to an aminophenylacetylene according to claim 1, characterized in that A mixed solution of iron and cerium nitrate in a certain ratio is impregnated on TiO2, dried, calcined in a muffle furnace in an air atmosphere at 200-500 DEG C for 2-5 h.