خدابخش نیکنام

Silica-bonded S-sulfonic acid is employed as a recyclable catalyst for the synthesis of naphthoxazinone derivatives from the reaction of ?-naphthol, aromatic aldehydes and urea at 150?C under solvent-free conditions. The heterogeneous catalyst was recycled for five runs after the reaction of ?-naphthol, benzaldehyde and urea without losing its catalytic activity.