A Protocol for the Synthesis of CFH-Containing Pyrazolo[1,5- c]quinazolines from 3-Ylideneoxindoles and in Situ Generated CFHCHN.

Herein is disclosed a selective and facile approach for the construction of CFH-containing pyrazolo[1,5- c]quinazolines from easily accessible 3-ylideneoxindoles and in situ generated CFHCHN. The reaction involving a [3 + 2] cycloaddition/1,3-H shift/rearrangement/dehydrogenation cascade proceeded smoothly at room temperature in the absence of catalyst and additive. Moreover, this metal-free process along with mild conditions is desirable and valuable for the pharmaceutical industry. Importantly, this reaction features a broad substrate scope, good functional group tolerance, and gram-scale synthesis.