One pot synthesis of N-ethylaniline from nitrobenzene and ethanol

Abstract

A novel method for the one pot synthesis of N-alkyl arylamines from nitro aromatic compounds and alcohols is proposed through the combination of the aqueous-phase reforming of alcohol for hydrogen production, the reduction of nitro aromatic compounds for the synthesis of aromatic amine and the N-alkylation of aromatic amine for the production of N-alkyl arylamine over an identical catalyst under the same conditions of temperature and pressure in a single reactor. In this process, hydrogen generated from the aqueous-phase reforming of alcohols was used in-situ for the hydrogenation of nitro aromatic compounds for aromatic amine synthesis, followed by N-alkylation of aromatic amine with alcohols to form the corresponding N-alkyl arylamines at a low partial pressure of hydrogen. For the system composed of nitrobenzene and ethanol, under the conditions of 413 K and P N 2 = 1 MPa, the conversion degrees of nitrobenzene and aniline were 100%, the selectivity to N-ethylaniline and N, N-diethylaniline were 85.9% and 0%-4%, respectivity, after reaction for 8 h at the volumetric ratio of nitrobenzene : ethanol : water = 10 : 60 : 0. The selectivity for N, N-diethylaniline production is much lower than that through the traditional method. In this process, hydrogen and aromatic amines generated from the aqueous-phase reforming of alcohols and hydrogenation of nitro aromatic compounds, respectively, could be promptly removed from the surface of the catalyst due to the occurrence of in-situ hydrogenation and N-alkylation reactions. Thus, this may be a potential approach to increase the selectivity to N-alkyl arylamine.

Controlled and Chemoselective Hydrogenation of Nitrobenzene over Ru@C60 Catalysts

“…Table shows the results obtained with the Ru@C 60 samples at different Ru/C 60 ratios (see Figure S6 in the Supporting Information for the evolution of the conversion over time). The main reaction products were AN and CA; DCA and N -ethylaniline (AN-Et), which is formed from N-alkylation of aniline due to reaction with the solvent, , were the only detected byproducts. All catalysts were found to be active for NB hydrogenation.…”

A resource recycling technique of hydrogen production from the catalytic degradation of organics in wastewater

“…Otherwise, alkylation of CO and/or CO 2 with H 2 [23] and hydrogenation of C x H y could lead to the formation of light alkanes such as CH 4 . Furthermore, organics adsorbed on the surface of catalyst may be also undergo hydrogenation, dehydrogenation or hydrolysis to form some organic intermediates, such as hydrogenation of phenol to cyclohexanone and cyclohexanol, hydrogenation of nitrobenzene to aniline, hydrogenolysis of aniline to benzene and hydrolysis of aniline to cyclohexanol [21,22] . Thus, an efficiency catalyst for the degradation of organics in water into H 2 with high selectivity should possess high catalytic activity for the WGS reaction, the aqueous phase reforming of C x H y and the cleavage of C-C bonds, but it does not possess high catalytic activity for the alkylation and hydrogenation.…”

“…An identical experimental result has been derived from the study about H 2 production from ethylene glycol by the APR over Pt catalysts supported on γ-Al 2 O 3 modified with Ce and Mg [20] . Meanwhile, a novel liquid system of catalytic hydrogenation [21] and one pot synthesis of N-ethylaniline from nitrobenzene and ethanol [22] have been proposed by using the active hydrogen generated in-situ from the APR of oxygenated hydrocarbons for the hydrogenation of organic compounds in liquid phase. In the present work, H 2 production from the catalytic degradation of organic pollutants, such as phenol, aniline, nitrobenzene, THF, toluene, DMF and cyclohexanol, to reach the resource recycling by the APR over the Raney Ni, Sn-Raney-Ni or Pd/C catalysts under mild conditions has been investigated.…”

Synthesis of 2-Methylbenzimidazole in Continuous Flow: Mechanism of Cu–Pd/(K)γ-Al2O3-Catalyzed Deactivation and Regeneration

“…When compared to a batch setting, a continuous flow reaction allows for finer control over the contact duration between intermediate species and catalytic activity, potentially improving selectivity. 29,30 In a trickle-bed catalytic reactor, the "alcohol dehydrogenation-hydrogen transfer-hydrogenation" coupling reaction system 31,32 was employed for the one-step synthesis of benzimidazole compounds. This approach provides benefits such as a high conversion rate, high selectivity, resistance to equipment corrosion, process simplification, and environmental friendliness.…”

“…Conventional synthetic procedures necessitate extensive equipment, particularly when employing inorganic acids and other compounds that generate significant wastes, harm the environment, entail lengthy reaction cycles, possess low atom economy, and involve hazardous solvents. − A majority of synthetic processes rely on batch production, which presents inconvenience in production, challenging catalyst recovery and separation, and an inability to simultaneously fulfill the three requirements of green chemistry, high-efficiency yield, and industrial-scale production. When compared to a batch setting, a continuous flow reaction allows for finer control over the contact duration between intermediate species and catalytic activity, potentially improving selectivity. , In a trickle-bed catalytic reactor, the “alcohol dehydrogenation-hydrogen transfer-hydrogenation” coupling reaction system , was employed for the one-step synthesis of benzimidazole compounds. This approach provides benefits such as a high conversion rate, high selectivity, resistance to equipment corrosion, process simplification, and environmental friendliness .…”