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.