7,8,9-trimethyl-1-phenyl-3H-pyrrolo[2,1-d][1,2,5]triazepin-4(5H)-one. Synthesis and reactions

A strategy was developed for the synthesis of 7,8,9-trimethyl-1-phenyl-3H-pyrrolo[2,1-d][1,2,5]-triazepin-4(5H)-one, reactions of its functionalization at the С4 atom and aza rings fusion at the С4‒N3 bond were explored. The formation mechanism of the pyrrolo-1,2,5-triazepinone scaffold was suggested.