Catalytic effects of some keggin-type Heteropoly Acids and polyoxometalates on selective nitration of phenols
K. amani*, f. maleki
Department of Chemistry, College of Science, University of Kurdistan, Sanandaj, Iran
(Received 22 August 2006, Accepted 14 January 2007)
Catalytic amounts of heteropoly acids and polyoxometalates promoted mononitration of phenolic compounds using iron(III) nitrate nonahydrate and bismuth(III) nitrate pentahydrate in dichloromethane at room temperature. Tungstophosphoric acid cesium salt, Cs2.5H0.5PW12O40, in a heterogeneous phase, exhibited significant rate enhancement of reactions as well as ortho selectivity without over-nitration and oxidation byproducts.
Keywords: Heteropoly acid, Polyoxometalate, Nitration, Phenol, Iron(III) nitrate, Bismuth(III) nitrate