Introduction of a triflate group into sterically-hindered positions in 1-aryl-4,6-diamino-1,3,5-triazines and their dimroth rearrangement products

Decomposition of 1-(azidophenyl)-4,6-diamino-1,3,5-triazines 11–13 and their 4-amino-6-(azidoanilino)-1,3,5-triazine isomers 31–33 in trifluoromethanesulphonic acid at 0° led to the introduction of the triflate group (OSO₂CF₃) into the aryl group. This method can be employed to introduce a bulky substituent into the hindered position ortho to the triazinyl substituent. Dimroth rearrangement of 1-(aryl)-4,6-diamino-1,3,5-triazines is best effected in refluxing ethanolic pyridine.