1,2,4-Triazolidine-3,5-dione 1H-1,2,4-Triazole-3,5(2H,4H)-dione 3,5-Dihydroxy-1,2,4-triazole 3232-84-6 Bicarbamimide NSC1892 Urazol Urazole Urazole bicarbamide s-Triazole-2,5-diol s-Triazole-3,5-diol