Reaction of 6-hydratino 1,5-diphenyl-1H-pyrazolo[3,4-d]pyrimidime-4-imine with aromatic aldehyde in presence of Preyssler catalyst yielded 8-aryl 1H-pyrazolo[4,3-e][1,2,4]triazolo[4,3-a] pyrimidine-4(5H) imine The performance of different form of Preyssler's anions including H-14[NaP5W30O110], H-14-P-5, mixed-addenda H-4[NaP5W29MoO110], H-14-P5MO; silica supported H-14[NaP5W30O110]/SiO2 and H14P5/SiO2 have been investigated. The reaction results were compared with that of a conventional acid catalyst (H2SO4). (c) 2006 Elsevier B.V. All tights reserved.