Antibacterial Evaluation of Some 3-Amino-1H-Pyrazolo[1,2-b]Phthalazine-2-Carboxamides by using Fish Scale Hydroxyapatite as a Heterogeneous Catalyst

Fish scale hydroxyapatite (FS-HAP) has been used as an efficient catalyst for the synthesis of 3-amino-1H-pyrazolo[1,2-b]phthalazine-2-carboxamide derivatives via the one-pot, three-component cyclocondensation reactions of aromatic aldehydes with cyanoacetamide and phthalhydrazide under solvent-free condition. FS-HAP has been characterized by FT-IR, XRD, SEM and EDS techniques. The synthesized compounds were evaluated for their in vitro antibacterial activity against gram-positive (Bacillus cereus, Bacillus aryabhattai, Bacillus megaterium, Staphylococcus aureus) and gram-negative (Serratia marcescens, Bacillus Pseudomonas putida, Escherichia coli, Enterobacter cloacae) bacteria. Tetracycline and erythromycin were used as standard antibiotics in this investigation. In the present protocol, we have achieved remarkable yields of the product in shorter reaction time and the catalyst was easily recovered and reused.