Cascade synthesis of the first imidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazine derivative

(Z)-7-(3,5-Di-tert-butyl-6-oxocyclohexa-2,4-dien-1-ylidene)-1,3-dimethyl-3a,9a-diphenyl-1,3 a,4,9 a-tetrahydroimidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazine-2,8(3H,7H)-dione was obtained by aldol condensation of 3,5-di-tert-butyl-1,2-benzoquinone with 1,3-dimethyl-3a,9a-diphenyl-3,3a,9,9a-tetrahydroimidazo[4,5-e]thiazolo[3,2-b][1,2,4]triazine-2,7(1H,6H)-dione followed by intramolecular thiazole ring-opening/closing in the condensation primary adduct.