1-(9-Methyl-11-sulfanyl-idene-8-oxa-10,12-diaza-tricyclo-[7.3.1.0]trideca-2,4,6-trien-13-yl)ethanone.

The six-membered oxacyclo-hexene ring of the title compound, C(13)H(14)N(2)O(2)S, is fused with the benzene ring and the quarternary C atom lies above the plane of the benzene ring by 0.229 (8) Å, whereas the methine C atom (which bears the acetyl substituent) lies below this plane by 0.595 (8) Å. The oxacyclo-hexene ring is also fused with the sofa-shaped 2,6-diaza-cyclo-hexa-none ring. The methine C atom that belongs to both six-membered rings lies above the mean plane of the other five atoms (r.m.s. deviation = 0.077 Å) by 0.759 (5) Å. In the crystal, N-H⋯S hydrogen bonds link adjacent mol-ecules into a linear chain.

1-(2-Oxo-3,4-dihydro-2H-1,3-benzoxazin-4-yl)urea monohydrate.

The organic molecule in the title hydrate, C(9)H(9)N(3)O(3)·H(2)O, was obtained by the condenstation of salicylic aldehyde with urea in acetonitrile. The oxazine ring adopts a slightly distorted sofa conformation, with the N atom deviating from the plane passing through the other atoms of the ring by 0.267 (2) Å. The crystal structure displays inter-molecular N-H⋯O and O-H⋯O hydrogen bonding.