Journal of Molecular Catalysis A-Chemical, Vol.259, No.1-2, 213-217, 2006
Preyssler heteropolyacid [NaP5W30O110](14-), as a new, green and recyclable catalyst for the synthesis of [1,2,4]triazino[4,3-b][1,2,4,5]tetrazines
Catalytic performance of Preyssler, H-14[NaP5W30O110], and Keggin, H-3[PW12O40], heteropolyacids as pure and supported on silica, H-14[NaP5W30O110]/SiO2, H-3 [PW12O40]/SiO2, have been studied in cyclocondensation of 4-amino-3-hydrazino-6-methyl-1,2,4-triazin-5(2H)-one (4-AHMT) with orthoesters. The catalytic activity of various forms of these catalysts in different solvents was compared with other classical catalysts, such as H2SO4 and HY-zeolite. In all cases the best yields were obtained, using H-14[NaP5W10O110]. (c) 2006 Elsevier B.V. All rights reserved.