2 2 6 6 tetramethyl 3 5 heptanedione

The reagents: 3-amino-1,2,4-triazole, acetylacetone, 1,3-diphenyl-1,3-propanedione, 2,2,6,6-tetramethyl-3,5-heptanedione, 6-methyl-2,4-heptanedione, diphenyl sulfoxide, tetrahydrothiophene-1-oxide, and K₂PtCl₄ were purchased from Sigma Aldrich (St. Louis, MO, United States), whereas the inorganic salts and solvents of analytical grade from Avantor Performance Materials Poland S.A. (Gliwice, Poland). All chemicals and solvents obtained commercially were used without further purification.
The 5,7-disubstituted derivatives of 1,2,4-triazolo[1,5-a]pyrimidine were obtained according to the Bülow and Haas [19 (link),20 (link)] method by the condensation of 3-amino-1,2,4-triazole with corresponding diketones such as: acetylacetone for (dmtp), 6-methyl-2,4-heptanedione for (ibmtp), 2,2,6,6-tetramethyl-3,5-heptanedione for (dbtp) and 3,5-diphenyl-1,3-propanedione for (dptp).

K₂PtCl₄, 3-amino-1,2,4-triazole (98%), 6-methyl-2,4-heptanedione (99%), 2,2,6,6-tetramethyl-3,5-heptanedione (98%), malonic acid and cyclobutane-1,1-dicarboxlic acid were purchased from Sigma Aldrich (Merck, St. Louis, MO, USA), whereas inorganic salts and solvents of analytical grade were purchased from Avantor Performance Materials Poland S.A (Gliwice, Poland).
5,7-Disubstituted derivatives of 1,2,4-triazolo[1,5-a]pyrimidines were prepared according to the Bülow and Haas method by the reaction of 3-amino-1,2,4-triazolewith 6-methyl-2,4-heptanedione for ibmtp and 2,2,6,6-tetramethyl-3,5-heptanedione for dbtp [28 (link)]. Disilver malonate (Ag₂C₃H₂O₄) and disilver cyclobutane-1,1-dicarboxylate (Ag₂C₆H₆O₄) were prepared by the reaction of AgNO₃ with malonic or cyclobutane-1,1-dicarboxylic acid by a known method [29 (link)].