Synthesis and characterization of 9-methyl-2-morpholin-4-yl-8-substituted phenyl-1H-purine derivatives using polyphosphoric acid (PPA) as an efficient catalyst
We demonstrate the synthesis of various purine derivatives through the coupling of N4-methyl-2-morpholin-4-yl-pyrimidine-4,5-diamine with various aldehydes by usingpolyphosphoricacid (PPA) as an efficient catalyst in DMF at reflux temperature. The PPA catalyst gave better yields (70–85%) in short reaction times (45–60 min). This commercially available cheap catalyst is more active than many reported