Catalytic transfer hydrogenation:: o-nitro anisole to o-anisidine, some process development aspects

The catalytic transfer hydrogenation of o-nitro anisole to o-anisidine was studied in the temperature range 35-85 degreesC with ammonium formate as H-donor and iso-propanol as solvent using Pd/C as catalyst above agitation speed 1000 rpm. The substrate feed concentration was varied in the range from 0.068 to 0.341 kmol/m(3) while catalyst loading was in the range 1.25-10% (w/w) of o-nitro anisole. The intermediate, hydroxylamine, was detected. In 130 min, all o-nitro anisole was converted with 99% selectivity towards o-anisidine. The catalyst has considerable reusability and was regenerated after deactivation without any significance loss in activity. Reliable methods for product separation and treatment of aqueous stream obtained after washing and solvent recovery are proposed. The possibility of Fenton Chemistry to treat aqueous waste stream was explored and found suitable. (C) 2004 Elsevier B.V. All rights reserved.