Synthesis of new functionalized derivatives of indolo[2,3-e][1,2,4]-triazolo-[4,5-b]-1,2,4-triazine

Abstract
New functionalized 1,2,4-triazolo-[4,3-b]-1,2,4-triazino-[5,6-b]indole derivatives were synthesized via reaction of the hydrazonoyl halides with 5H-2,3-dihydro-1,2,4-triazino[5,6-b]indole-3-thione or its 3-methylthio derivative. The mechanism and the regioselectivity of the studied reactions have been discussed.