Synthesis and nematicidal activities of 1,2,3-benzotriazin-4-one containing 4,5-dihydrothiazole-2-thiol derivatives against Meloidogyne incognita

A series of novel 1,2,3-benzotriazin-4-one derivatives containing 4,5-dihydrothiazole-2-thiol were synthesized and characterized by H-1 NMR, C-13 NMR, F-19 NMR and HRMS. The bioassay results showed that compounds 3-(3-((4,5-dihydrothiazol-2-yl)thio)propyl)-7-methoxybenzo[d][1-3]triazin-4(3H)-one, 3-(3-((4,5-dihydrothiazol-2-yl)thio)propyl)-6-nitrobenzo[d][1-3]triazin-4(3H)-one, 7-chloro-3-(3-((4,5-dihydrothiazol-2-yl)thio)propyl)benzo[d][1-3]triazin-4(3H)-one exhibited good control efficacy against the cucumber root-knot nematode disease caused by Meloidogyne incognita at the concentration of 10.0 mg L-1 in vivo. Compound 7-chloro-3-(3-((4,5-dihydrothiazol-2-yl)thio)propyl)benzo[d][1-3]triazin-4(3H)-one showed excellent nematicidal activity with inhibition 68.3% at a concentration of 1.0 mg L-1. It suggested that the structure of 1,2,3-benzotriazin-4-one containing 4,5-dihydro-thiazole-2-thiol could be optimized further.