052

Title:

Mechanochemical nitration of organic compounds

Discipline: Chemical and Materials engineering

Presenter:

Ashvin

Abstract:

A solvent-free approach is being developed for conducting organic nitration reactions mechanochemically. The present effort is focused on nitration of different aromatics compounds with environmentally benign reagents. Initial success with nitration reaction of toluene using sodium nitrate as a source of nitronium with molybdenum oxide as a catalyst prompted further tests with various catalysts and other precursors. To check the effects of Lewis and Bronsted acidities, a wide range of catalysts including MoO3, WO3, V2O5, Fe2O3, TiO2, Bi2O3, γ-Al2O3, MnO2 and HZSM-5 (with Si/Al ratios of 39 and 360) were explored for conducting the toluene-sodium nitrate reaction. A planetary ball mill was used at room temperature with 6.35-mm diameter steel balls as milling media. Yields and selectivities were compared for relatively short, 30-minute milling runs. Each milling run, carried out at 350 rpm, included 41.63 g of catalyst, 1.67 g of NaNO3 and 0.5 ml of toluene. Clearly detectable yields of nitroproducts were observed MoO3, WO3, and V2O5. The highest yield and p/o selectivity of mono-nitrotoluene were observed with MoO3. Further, the catalysts were pre-milled for 15, 30 and 120 minutes to test the effect of the generated surface area on the subsequent 30 min reaction. It was found that homogenizing the sodium nitrate over the molybdenum oxide catalyst improved the yields substantially. The effect of the reactant molar ratio was studied by varying the relative amounts and a maximum was obtained at molar ratios 2-5.

Author(s):

Ashvin Kumar Vasudevan, Dr. Edward L. Dreizin, Dr. Mirko Schoenitz

Funding Acknowledgements:

Stragetic Environmental research and development program