A novel porphyrin-initiated amine-functionalized poly-3,3-bis(chloromethyl) oxetane (PBCMO-amine) dendritic polymer was effectively synthesized. Characterization using the UV-vis, IR, NMR, PXRD, TG, and FE-SEM spectroscopy and microscopy enabled one to assess the structural and morphological stability of the PBCMO-amine. Its catalytic activity was studied in one-pot fourcomponent solvent-free synthesis of pyrazolopyranopyrimidinone and pyranopyrazole using aldehyde, ethylacetoacetate, hydrazine hydrate, and barbituric acid/malononitrile by simple ultrasonic irradiation. Because of the water-soluble nature of PBCMO-amine, the catalyst could be separated and reused without the loss of its activity.