Synthesis of 2-amino-4,6-diarylnicotininitriles using 3-propyldiethylenetriamine-silica as a recyclable solid base catalyst

A simple and ecient procedure for the preparation of 3- propyldiethylenetriaminesilica (PDTAS) by reaction of 3-chloropropylsilica with diethylene-triamine is described. 3-propyldiethylenetriaminesilica is employed as a recyclable base catalyst for the synthesis of 2-amino-4,6-diarylnicotininitrile from the reaction of acetophenone derivatives, aromatic aldehydes, malononitrile, and ammonium acetate under solvent-free conditions at 100C. The heterogeneous solid base catalyst was recycled for four runs upon the reaction of 4-chloroacetophenone, 4-chloroenzaldehyde, malononitrile, and ammonium acetate without losing its catalytic activity.