The reaction of 3,4-diamino-1,2,5-oxadiazoles with formaldehyde

(2Z,3Z)-3,4-Dihydro-2H-1,4-benzothiazine-2,3-dione dioxime dihydrate

In the mol­ecule of the title compound, C₈H₁₁N₃O₄S, the thia­zine ring adopts an envelope conformation. In the crystal structure, inter­molecular N—H⋯O, O—H⋯O and O—H⋯N hydrogen bonds link the mol­ecules.

(2Z,3Z)-Quinoxaline-2,3(1H,4H)-dione dioxime

The asymmetric unit of the title compound, C(8)H(8)N(4)O(2), contains one half-mol-ecule; a twofold rotation axis bisects the molecule. An intra-molecular N-H⋯O hydrogen bond results in the formation of a five-membered ring, which displays an envelope conformation. In the crystal structure, inter-molecular O-H⋯N hydrogen bonds link the mol-ecules.