Synthesis and biological activity of organotin 4-methyl-1,2,3-thiadiazole-5-carboxylates and benzo[1,2,3]thiadiazole-7-carboxylates.

A series of organotin 4-methyl-1,2,3-thiadiazole-5-carboxylates and benzo[1,2,3]thiadiazole-7-carboxylates have been synthesized and characterized by NMR ((1)H, (13)C, and (119)Sn), IR, and elemental analyses. The structure of the dimeric complex {[(BTHCO(2))SnEt(2)](2)O}(2) (BTH represents benzo[1,2,3]thiadiazol-7-yl) has been further confirmed by X-ray diffraction crystallography. Assessment for fungicidal activity indicates that all of the newly synthesized compounds exhibit good growth inhibition against Alternaria solani , Cercospora arachidicola , Gibberella zeae , Physalospora piricola , and Botrytis cinerea .