Synthesis of Imidazo[4,5‐e]thiazolo[2,3‐c]‐1,2,4‐triazine‐2,8‐diones via a Rearrangement of Imidazo[4,5‐e]thiazolo[3,2‐b]‐1,2,4‐triazine‐2,7‐diones in the Reaction with Isatins.

An aldol condensation/skeletal rearrangement protocol for the synthesis of 1,3-dialkyl-7-(2-oxo-1,2-dihydro-3H-indol-3-ylidene)-1,3a,4,9a-tetrahydroimidazo[4,5-e]thiazolo[2,3-c]-1,2,4-triazine-2,8(3H,7H)-diones in good to high yields via a one-pot reaction of 1,3-dialkyl-3,3a,9,9a-tetrahydroimidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-2,7(1H,6H)-diones and 1H-indole-2,3-diones (isatins) or through the generation and rearrangement of 1,3-dialkyl-6-(2-oxo-1,2-dihydro-3H-indol-3-ylidene)-3,3a,9,9a-tetrahydroimidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-2,7(1H,6H)-diones has been developed.