Synthesis and Herbicidal Activity of 2-(2-Oxo-3-pyridyl-benzothiazol-6-yloxy)hexanoic Acids

• DOI: 10.1021/acs.jafc.3c08213
• Publication Date: 2024-03-26T02:05:21Z
• Authors: Yuqian Huang; Zhanbin Li; Yu Chen; Wenqi Li; Shaopeng Wei; Zhiqin Ji
• Keywords: Moiety; Hexanoic acid; Lead compound; Benzothiazole

The discovery of a lead compound is fundamental to herbicide innovation, but the limited availability valuable compounds has hindered their development in recent years. By utilizing structural diversity-oriented inactive group strategy, 3-(2-pyridyl)-benzothiazol-2-one was identified as promising scaffold for herbicides, starting from benzothiazole which an moiety commonly found herbicides such mefenacet, benazolin, benzthiazuron, and fenthiaprop-ethyl. To investigate structure–activity relationship (SAR) these chemicals, series 2-(2-oxo-3-pyridyl-benzothiazol-6-yloxy)hexanoic acid derivatives (VI01 ∼ VI28) were synthesized through classical nucleophilic SNAr reaction using halogenated pyridines 6-methoxybenzothiazole-2-one. chemical structures all title confirmed by NMR MS analysis. Petri dish assays indicated that many exhibited potent herbicidal activity against both broad-leaf weeds grass at 1.0 mg/L. SAR analysis revealed presence trifluoromethyl 5-position pyridine essential activity. Furthermore, carboxylic esters exhibit higher compared amides free acids, decreased with extension carbon chain. postemergence VI03 16 species tested pot experiments greenhouse. demonstrated comparable efficacy controlling broadleaf superior carfentrazone ethyl. present study unveiled novel molecular exhibiting remarkably These findings are anticipated provide insights advancement new offer alternative approach managing resistant weeds.