3-Ethyl-6-(4-fluoro-phen-yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thia-diazine.

In the title compound, C(12)H(11)FN(4)S, the thia-diazine ring adopts a twist-boat conformation. The dihedral angle between the triazolothia-diazine system and the benzene ring is 10.54 (9)°.

4-[(E)-(4-Fluoro-benzyl-idene)amino]-3-methyl-1H-1,2,4-triazole-5(4H)-thione.

In the asymmetric unit of the title compound, C(10)H(9)FN(4)S, there are two independent mol-ecules in which the dihedral angles between the 1,2,4-triazole and benzene rings are 36.85 (10) and 7.81 (10)°.

3-Ethyl-4-[(E)-(4-fluoro-benzyl-idene)amino]-1H-1,2,4-triazole-5(4H)-thione.

In the title compound, C(11)H(11)FN(4)S, the dihedral angle between the 1,2,4-triazole ring and the benzene ring is 25.04 (12)° and an intra-moleuclar C-H⋯S inter-action leads to an S(6) ring. In the crystal, inversion dimers linked by pairs of N-H⋯S hydrogen bonds generate R(2) (2)(8) loops.