X-ray structure of 6-phenyldiquino[3,2-b;5,6-b '] [1,4]thiazine

The title compound (C24H15N3S) is monoclinic, with a = 10.816(1), b = 8.193 (1), c = 10.892(1), beta = 104.20(1)degrees and space group P2(1). The mole cule is folded with the central ring, in a boat conformation. It can also b e considered as folded around the C-C axis between the thiazine and pyridin e rings. The butterfly folding angle between the two quinoline planes is 20 .5(1)degrees and between the planes of the two halves of the thiazine ring is 30.6(1)degrees. The phenyl substituent is in an equatorial location with respect to the thiazine ring with the C-N . . .S angle of 163.0(2)degrees. The phenyl plane nearly bisects the pentacyclic ring system and is nearly perpendicular to the C(2), C(3), C(12), C(13) plane.