using pd oh 2 c as a catalyst under 50 psi of hydrogen to yield the 5 hydroxyamino derivative contaminated with about 10 15 of the corresponding 5 amino derivative 2 1 3 dioxolanyl 4 methyl 5 hydroxyaminopyridine was easily purified by recrystallization from ethanol the structure was assigned by nmr mass spectroscopy and elemental analysis during the reduction process the rate of absorption of hydrogen decreased considerably after the formation of the 5 hydroxyamino derivative 2 1 3 dioxolanyl 4 methyl 5 hydroxyaminopyridine and the reaction was terminated at this stage when the reaction was allowed to proceed until the absorption of hydrogen was complete about 24 h however the 5 amino derivative 2 1 3 dioxolanyl 4 methyl 5 aminopyridine was obtained in nearly quantitative yield condensation of 2 1 3 dioxolanyl 4 methyl 5 hydroxyaminopyridine with thiosemicarbazide in the presence of concentrated hydrochloric acid followed by treatment with sodium bicarbonate afforded the desired 5 hydroxyamino 4 methyl 2 formylpyridine thiosemicarbazone melting points were determined with a thomas hoover unimelt apparatus and are uncorrected 1 h nmr spectra were recorded on a varian em 390 90 mhz nmr spectrometer or a bruker wm 500 500 mhz spectrometer with me 4 si as the internal reference the mass spectra at 70 ev were provided by the yale university chemical instrumentation center tlc was performed on.