CeCl3-promoted one-pot synthesis of multisubstituted bispyrano[2,3-c]pyrazole derivatives

摘要

A simple and efficient method was developed for the synthesis of multisubstituted bispyrano[2,3-c]pyra-zole derivatives via one-pot reaction of β-keto esters, hydrazine (or phenylhydrazine), terephfhalaldehyde, and malononitrile in the presence of CeCl3·7H2O (10 mol%) as a catalyst. This method provides the products in good yields after a simple workup procedure without further purification.