fe3o4@sio2-so3h

In the present study, a simple and rapid method using an effective heterogeneous nanomagnetic catalyst, Fe3O4@SiO2-SO3H, was used to prepare the 2-arylbenzoxazoles derivatives by a condensation reaction of aromatic aldehydes with 2-aminophenol without using solvent and at a temperature of 50 0C. This catalyst is magnetically recycled and reused several times without reducing its catalytic activity. It was demonstrated that Fe3O4@SiO2-SO3H is an economic catalyst that can be used several times without reducing the catalytic properties. Purifying of the final products was simple and easy, and the percentage of catalyst performance was satisfactory.

A new efficient method for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones and spiroquinazolinones via a condensation reaction of aldehydes and ketones with anthranilamide in the presence of nano Fe3O4@SiO2-SO3H as catalyst in ethanol has been described. The reactions are completed in short times, and the corresponding dihydroquinazolinones are produced with high yields. The present procedure has several advantages, including short reaction times, high yields of products, facile experiment, simple work-up, eco-friendly reaction conditions, and reusability of the catalyst. The catalyst could simply be separated and recovered by an external magnet and reused in subsequent reactions with no considerable loss in activity.