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A cost-effective and eco-friendly synthesis of benzopyrano[2,3-d]pyrimidine derivatives has been developed via three component one-pot tandem approach by condensing different salicylaldehydes and secondary amines with malononitrile in the presence of TiO2–SiO2 catalyst at 80°C under solvent-free conditions. Mild experimental conditions, reusability of the catalyst, and cost effectiveness are the merits of this procedure. Compounds 4g, 4h, and 4i bearing 2-OMe group on the hydroxyphenyl group linked to the central carbon present in between the two nitrogen atoms of the pyrimidine ring were found to exhibit good antioxidant activity while other compounds have moderate antioxidant activity.

A simple and efficient method has been developed for the synthesis of β-amino carbonyl compounds from aromatic ketones, aldehydes and amines by Mannich reaction in the presence of amberlyst-15 as a reusable heterogeneous catalyst at room temperature under solvent-free conditions. The noteworthy advantages of the present method are short reaction times, good product yields, simple procedures and use of non-toxic catalyst.

New 2-amino-N-hydroxybenzamide derivatives (3a–j) have been synthesized in good to excellent yields from the reaction of isatoic anhydride with different hydroxamic acids. All the compounds of the series were screened against both Gram-positive and Gram-negative bacteria and fungi, and some of them have antibacterial and antifungal activities compared to the standard drugs.