2-Methyl­sulfanyl-1,2,4-triazolo[1,5-a]quinazolin-5(4H)-one

The non-H atoms of the title compound, C₁₀H₈N₄OS, lie approximately in a common plane (r.m.s. deviation = 0.058 Å). In the crystal, two mol­ecules are linked across a center of inversion by a pair of N—H...N hydrogen bonds, forming a a dimer.

2-Methyl­sulfonyl-1,2,4-triazolo[1,5-a]quinazolin-5(4H)-one

The triazoloquinazoline fused-ring system of the title compound, C₁₀H₈N₄O₃S, is essentially planar (r.m.s. deviation = 0.027 Å). In the crystal, adjacent mol­ecules are linked by N—H...O_sulfon­yl hydrogen bonds, generating a helical chain running along the b axis.