Knoevenagel condensation of isatins with malononitrile/ethyl cyanoacetate in the presence of sulfonic acid functionalized silica (SBA-Pr-SO3H) as a new nano-reactor

The Knoevenagel condensation between isatins and active methylene compounds like malononitrile and ethyl cyanoacetate to prepare 2-oxoindolin-3-ylidene malononitrile/ cyanoacetates is described. The reactions occur in the presence of sulfonic acid functionalized silica SBA-15 (SBA-Pr-SO3H) in an aqueous medium giving excellent yields of the products in short reaction times. SBA-Pr-SO3H with a pore size of 6 nm is found to be an efficient and environmentally benign catalyst for this reaction

Application of sulfonic acid functionalized nanoporous silica (SBA-Pr-SO3H) in the solvent free synthesis of (E)-arylidene-1,3-dihydroindole-2-ones

An efficient and green condensation reaction is developed for the synthesis of (E)-arylidene-1,3-dihydroindole-2-ones; (1), using heterogeneous nanoporous acid catalyst of SBA-Pr-SO3H with pore size, 6 nm in solvent free condition. Arylidene-1,3-dihydroindole-2-ones have many pharmaceutical properties such as Tyrosin kinase inhibiton. This method has the advantages of short reaction time, isolation ease of the products, excellent yields and recyclable catalyst