organic compounds
The structure of the title compound, C18H16N2O4S, with a new chiral pyrido[3′,2′:5,6][1,2]thiazino[3,2-c][1,4]oxazine ring system, is described. Both partially saturated thiazine and oxazine rings adopt diplanar conformations. The molecular packing is influenced by weak C—HO and π–π interactions.
organic compounds
In the structure of the title compound, C19H21N5O3S, the piperazine ring adopts a slightly deformed chair conformation, with puckering parameters Q = 0.534 (2) Å and θ = 22.2 (2)° and an almost flat configuration of the piperazine N atom bonded to the benzene ring. This deformation is caused by the strong conjugation effect of the lone pair of the N atom with the π-electron system of the benzene ring in the arylpiperazine part of the molecule. The molecular packing is influenced by weak π–π interactions of the isothiazolopyridine systems, with a shortest centroid-to-centroid separation of 3.5113 (14) Å between pyridine rings.