CENTRO DE INVESTIGACION Y DESARROLLO EN CIENCIAS APLICADAS "DR. JORGE J. RONCO"
Unidad Ejecutora - UE
congresos y reuniones científicas
HETEROSTRUCTURED ARGENTINEAN CLAYS AS EFFICIENT AND SELECTIVE CATALYSTS IN THE SYNTHESIS OF 1,5-BENZODIAZEPINES
M. MUÑOZ; G. SATHICQ; G. ROMANELLI; C. CABELLO; I. BOTTO
Congreso; XX International Materials Research Congress; 2011
Natural and modified Argentinean bentonite as catalysts in the synthesis of 1,5 benzodiazepine through a condensation reaction between o-phenylenediamine (OPDA) and excess of acetone as reactive and solvent at room temperature were studied. The modified clays were prepared by conventional methods and characterized by textural analysis (BET), electronic microscopy (ESEM-EDS), X ray diffraction technique (XRD), infrared (FTIR) and nuclear magnetic resonance (Al27-MAS NMR) spectroscopies. The original and modified materials found to be highly active and selective afford a high yield of the corresponding benzodiazepine. The effects of the modification of natural bentonite and reaction conditions such as temperature, time and catalyst amount were investigated. Catalysts were also successfully employed for the preparation of other derivatives of 1,5-benzodiazepine using substituted o-PDAs and ketones. In every case reactions were highly selective and were completed within 13 h. In all cases, the catalytic activity was excellent, showing 86%-90% isolated yields of the corresponding derivatives of 1,5-benzodiazepine. The easy work-up procedure and the recyclable catalyst make this methodology attractive for large-scale operations.