1-Methyl-2-mercapto-4,7-dihydroxy-1,3,5,6-tetrazaindene 1H-Imidazo[4,5-d]pyridazine-4,7-diol, 2-mercapto-1-methyl- 2-Mercapto-1-methyl-1H-imidazo[4,5-d]pyridazine-4,7-diol 5450-59-9 NSC10007