Efficient synthesis of novel functionalized dihydro-pyrazolo[3,4-d] pyridines via the three-component reaction using MgO/HAp as a sustainable catalyst

We report the preparation of the magnesium loaded hydroxyapatite (MgO/HAp) composite and characterization of its structural properties by different analytical techniques, namely powder XRD, BET, SEM, TEM and FT-IR analysis. We evaluated the catalytic activity of MgO/HAp for the synthesis of novel dihydropyrazolo[3,4-b] pyridine derivatives by three-component reaction of 1H-3-amino-1H-pyrazole, acetoacetanilide and different benzaldehydes in ethanol medium at room temperature (RT). The protocol offered excellent yields (92-97%) of the products in 20-25 min reaction time. Additionally, the spent catalyst was recycled up to five runs without noticeable loss of activity. Simple workup, robust synthesis, excellent yields, mild reaction conditions, reusability and avoid of chromatography purification are the advantages of the present protocol.

Automated summary

The study presents the preparation and characterization of magnesium loaded hydroxyapatite composite, and evaluates its catalytic activity for the synthesis of novel dihydropyrazolo[3,4-b] pyridine derivatives. The composite showed excellent yields, reusability, and simplicity in operation, making it a promising catalyst for organic synthesis.