Regioselectivity of cyclization of 1-(6-methyl-5-oxo-2,5-dihydro-1,2,4-triazin-3-yl)-4-arylthiosemicarbazides by treating with methyl iodide and dicyclohexylcarbodiimide
作者:R. I. Vas’kevich、P. V. Savitskii、E. B. Rusanov、V. I. Staninets
DOI:10.1134/s1070428010110138
日期:2010.11
1-(6-Methyl-5-oxo-2,5-dihydro-1,2,4-triazin-3-yl)-4-arylthiosemicarbazides treated with methyl iodide in the presence of sodium acetate in ethanol convert into 6-methyl-3-arylamino[1,2,4]-triazolo[4,3-b][1,2,4]triazin-7(1H)-ones. In reaction with dicyclohexylcarbodiimide 6-methyl-3-arylamino[1,2,4] triazolo[3,4-c][1,2,4]triazin-5(1H)-ones were obtained which at heating in alcohol solution in the presence of sodium acetate or at 262-272 degrees C underwent the Dimroth rearrangement to give 3-methyl-7-arylamino[1,2,4] triazolo[5,1-c][1,2,4]-triazin-4(8H)-ones.