2-Hydrazino-4-hydroxy-6-methylpyrimidine

The condensed 1,2,4-triazole ring of 577 was formed as a result of condensing the jS-D-ribofuranosylcarbodithioate 512 with 2-hydrazino-4-hydroxy-6-methylpyrimidine. Unlike the l,2,4-triazolo[l,5-c]pyrimidine analog 568, the l,2,4-triazolo[4,3-fl]pyrimidin-3-yl C-nucleoside 577 did not undergo Dimroth rearrangement (89MI5) (Scheme 154). 

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