Reaction of Pyrrolo[2,1-c][1,4]benzothiazine-1,2,4-triones with Indole

Pyrrolo[2,1-c][1,4]benzothiazine-1,2,4-triones are promising polyelectrophilic scaffolds for constructing complex heterocyclic structures. This work describes a synthetic approach to novel heterocyclic assemblies derived from them, specifically 3a-(1H-indol-3-yl)-1H-benzo[b]pyrrolo[1,2-d][1,4]thiazines, which contain fused pyrrolo[2,1-c][1,4]benzothiazine and a 1H-indole fragments. The proposed method is based on the Michael reaction between pyrrolobenzothiazinetriones and 1H-indole in the absence of catalysts and additives. The synthesized (1H-indolyl)benzo[b]pyrrolo[1,2-d][1,4]thiazines were evaluated for potential agrochemical and biotechnological applications as growth regulators of the green unicellular alga Chlorella vulgaris.