An Efficient and Eco-friendly MoO3–SiO2 Solid Acid Catalyst for Electrophilic Aromatic Nitration with N2O5

Abstract

Electrophilic aromatic nitration using N 2 O 5 as a green nitrating agent catalyzed by MoO 3 -SiO 2 under mild conditions has been described. A series of MoO 3 -SiO 2 catalysts with varying MoO 3 loadings (5-20 mol%) were prepared by sol-gel technique and characterized using FTIR, XRD, SEM, BET and NH 3 -TPD to study its surface properties. MoO 3 -SiO 2 shows good catalytic activity and reusability for the nitration of alkyl and halogen aromatics giving high conversions, but less efficiency for the deactivated aromatics. Reactions conducted under non-acidic conditions using N 2 O 5 makes the process safe and environmentally friendly.

Metal salts with highly electronegative cations as efficient catalysts for the liquid-phase nitration of benzene by NO2 to nitrobenzene

“…Nitrobenzene is a versatile starting material with many different applications in the commercial manufacturing of dye stuffs, explosives, plastics and pharmaceuticals [2]. Currently, the most benzene nitration processes employs a mixture of nitric and sulfuric acids [2,3].…”

“…Nitrobenzene is a versatile starting material with many different applications in the commercial manufacturing of dye stuffs, explosives, plastics and pharmaceuticals [2]. Currently, the most benzene nitration processes employs a mixture of nitric and sulfuric acids [2,3]. However, this mixed-acid system inevitably suffers from some serious disadvantages, such as poor yields of the desired products, severe corrosion of the facilities and the generation of large quantities of dilute sulfuric acid which inevitably results in environmental pollution [4].…”

Isolation, Characterization, and Identification of Catalytically Active Species in the MoO3/SiO2 Catalyst during Solid Acid Catalyzed Reactions

“…For example, MoO 3 /SiO 2 catalysts prepared by the sol-gel process were used for electrophilic aromatic nitration with N 2 O 5 . [13] Park et al used MoO 3 /SiO 2 prepared by using the wet impregnation technique for the isomerization of 2-butene to 1-butene. [14] In our group, a series of mesoporous MoO 3 /SiO 2 (1-20 mol % MoO 3 loading) solid acid catalysts were synthesized using the simple sol-gel technique with ethyl silicate-40 as a novel silica source and ammonium heptamolybdate as a molybdenum source and with no surfactant/template and hydrothermal treatment.…”

The application of nitrogen oxides in industrial preparations of nitro compounds

“…Nitration reactions to form C‐N bonds have been widely used for the preparation of nitro compounds in numerous areas of applied research . Owing to the widespread presence of nitro compounds in pharmaceuticals, natural products, organic intermediates, catalysts, and high energy density materials, the application of this process has been exceptionally broad. However, based on the principles of green chemistry, most industrial nitration processes are less environmentally‐friendly because they use nitric acid, nitrates, and nitrous esters as nitrating agents .…”