The title compound, C(9)H(7)Cl(2)N(3)OS, was synthesized by the reaction of 2,4-dichloro-phenoxy-acetic acid and thio-semicarbazide. The dihedral angle between the thia-diazole and benzene rings is 21.5 (2)°. In the crystal, inter-molecular N-H⋯N hydrogen bonding links the mol-ecules into chains along the b axis.

The methyl-ene C atom in the title compound, C(13)H(16)N(2)S, is connected to a five-membered thia-zole ring and a mesityl substituent. The rings are aligned at 75.4 (1)°. The amino substitutent inter-acts with the ring N atom of an adjacent mol-ecule by an inter-molecular N-H⋯N hydrogen bond, generating a helical chain running along the b axis.

The title compound, C(9)H(9)N(3)S, was synthesized by the reaction of 4-methyl-benzoic acid and thio-semicarbazide. The thia-diazol ring adopts a planar conformation and makes a dihedral angle of 31.19 (18)° with the phenyl ring. In the crystal, mol-ecules are linked by N-H⋯N hydrogen bonds.

The title compound, C(8)H(6)FN(3)S, was synthesized by the reaction of 3-fluoro-benzoic acid and thio-semicarbazide. The dihedral angle between the planes of the thia-diazole and benzene rings is 37.3 (2)°. In the structure, two crystallographically independent mol-ecules form a centrosymmetric dimer, in which two inter-molecular N-H⋯N hydrogen bonds generate an R(2) (2)(8) motif.

There is a twist in the title mol-ecule, C(15)H(11)ClN(2), as seen in the dihedral angle of 18.85 (9)° between the quinoline and benzene rings. A short C-H⋯N contact arises from this conformation and the amine H and quinoline N atoms are directed towards opposite sides of the mol-ecule. In the crystal, supra-molecular layers in the ab plane are mediated by C-H⋯π inter-actions.