A Facile Synthesis of Novel Dihydroindeno[1,2‐e][1,2,4]triazolo[3,4‐b][1,3,4]thiadiazines Using HTIB

Abstract

The synthesis of a series of 21 novel 3‐alkyl/aryl‐7/9‐methyl‐10,10a‐dihydroindeno[1,2‐e][1,2,4]triazolo[3,4‐b][1,3,4]thiadiazines (4) has been achieved by the cyclocondensation between 4/6‐methyl‐2‐tosyloxy‐1‐indanones (2) and 3‐alkyl/aryl‐4‐amino‐5‐mercapto‐1,2,4‐s‐triazoles (3). 4/6‐Methyl‐2‐tosyloxy‐1‐indanones (2) were readily accessible through hypervalent iodine oxidation of 4/6‐methyl‐1‐indanones using [(hydroxy)tosyloxyiodo]benzene (HTIB, Koser's reagent) in acetonitrile.