Triaminopyrimidine Based Porous Organic Polymers: Synthesis,Characterization and Catalytic Applications in One-pot Room Temperature Synthesis of Dihydropyranopyranes

摘要

Novel nitrogen-rich triaminopyrimidine based porous organic polymer (TAP-POP),was synthesized via a simple,cost-effective and catalyst-free Schiff base condensation between 2,4,6-triaminopyrimidine and terephthalaldehyde in N,N-dimethylformamide.The TAP-POP was characterized by FT-IR,Powder XRD,Solid-state ~(13)C and ~(15)N CP-TOSSNMR,TGA,BET,SEM and TEM analyses.This polymer containing lot of basic nitrogen sites,act as efficient heterogeneous base catalysts for the room temperature synthesis of dihydropyrano[3,2-c]chromenes and dihydropyrano[4,3-b]pyranes from aromatic aldehydes,malononitrile and 4-hydroxycoumarin/4-hydroxy-6-methyl-2H-pyran-2-one via a one-pot,three component reaction.This TAP-POP was easily recovered by simple filtration and was reused upto five times with only a marginal loss in its catalytic efficiency.