The title compound, C19H13N3S. is folded, with the central ring in a boar c
onformation. The folding angle between the two quinoline rings is 150.2 (1)
degrees. The 14-methyl substituent is in a quasi-axial orientation with res
pect to the thiazine ring. The S ... N-C-methyl angle is 120.1 (1)degrees.