Abstract
In the title compound, C
17
H
17
N
3
O
2
S, the phenyl ring is oriented at dihedral angles of 8.5 (2) and 1.17 (14)°, respectively, to the C=N—N plane and the fused aromatic ring. The thiazine ring adopts an envelope conformation with the S atom at the flap. In the crystal, a weak C—H⋯O interaction connects the molecules, forming a helical chain along the
a
axis.