Synthesis and antileukemic activities of furanyl, pyranyl, and ribosyl derivatives of 4-(3,3-dimethyl-1-triazeno)imidazole-5-carboxamide and 3-(3,3-dimethyl-1-triazeno)pyrazole-4-carboxamide.

From the reaction of silylated 4-(3,3-dimethyl-1-triazeno)imidazole-5-carboxamide (DTIC, 5) and 3-(3,3-dimethyl-1-triazeno)pyrazole-4-carboxamide (DTPC, 9) with 2-chlorotetrahydrofuran, we have isolated in both cases a single tetrahydrofuran-2-yl derivative. However, when silylated DTPC was reacted with 2-chlorotetrahydropyran, two tetrahydropyran-2-yl compounds were obtained, and these were shown to be positional isomers on the basis of 1H NMR and UV data. These furanyl and pyranyl derivatives were tested for antileukemic activity (L-1210, in vivo) and the results were compared with the results obtained for the corresponding ribosyl derivatives of DTIC and DTPC.