SYNTHESIS OF SOME N-ALKYLATED 1,2,4-TRIAZOLES, 1,3,4-OXADIAZOLES, AND 1,3,4-THIADIAZOLES BASED ON N-(FURAN-2-YLMETHYLIDENE)-4,6-DIMETHYL-1H-PYRAZOLO-[3,4-MPYRIDIN-3-AMINE

摘要

N-(Furan-2 -ylmethylidene)-4,6-dimethy1-1H-pyrazolo [3 ,4-b]pyridin-3 -amine was prepared and alkylated with the appropriate halo compounds to afford N-alkylated products. 2- [3 -(Furan-2 -ylmethylideneamino)-4,6 -dimethyl- 1 H-pyrazolo [3 ,4-b]pyridin1 -yl] acetohydrazide was converted into the key intermediate thiosemicarbazide which undergoes cyclization reactions under acidic and basic conditions to give 1,2,4-triazole, 1,3,4-oxadiazole, and 1,3,4-thiadiazole derivatives. Condensation of the hydrazide with monosaccharide aldoses gave the corresponding sugar hydrazones, which on treatment with acetic anhydride readily undergo cyclization reaction to afford oxadiazoline derivatives.