Franco Vairoletti, Paulina Rodríguez, Jorge Cantero, Margot Paulino, Natalia Alvarez, Javier Ellena, Gustavo Salinas, Gonzalo Hernández Dossi, Graciela Mahler, Cecilia Saiz,
Recently introduced to the market, benzamides represent a new chemical family for combating plant-parasitic nematodes. This work describes the design, synthesis and structural characterization of novel N-alkyl benzamides and evaluates their efficacy as nematicides.The prepared compounds presented cis/trans isomerism in solution, as evidenced by 1H-NMR spectra in CDCl3 and DMSO‑d6. Isomer assignment was achieved using a combination of experimental data and density functional theory (DFT) calculations, including 1H-NMR chemical shift predictions. For F-containing compounds, 19F-NMR predictions, conformational analysis and 1H-19F COSY experiments provided additional support. Among the studied compounds, terminal N-methyl cis isomers displayed higher 1H-NMR chemical shifts than the corresponding trans isomers, whereas 13C-NMR signals presented higher chemical shifts for the trans isomers compared to the cis ones.One of the compound's structures was further characterized in the solid state. Pyridine N-methylamide 7 yielded suitable crystals for X-ray diffraction of the trans isomer. The intermolecular interactions observed included non-classical C–H···O and C–H···F hydrogen bonds as well as a 4% contribution of Cl···F interactions. Infrared spectrum for 7 was analyzed and signals assigned with the aid of computational tools. All compounds were assayed against Caenorhabditis elegans. Among the N-alkylated benzamides, N-methyl-thioamide 10 showed the highest motility inhibition (56 ± 4% at 10 μM).
https://doi.org/10.1016/j.molstruc.2026.146455
@article{Vairoletti_2026, title={An integrated NMR and DFT study on the conformational preferences of N-alkyl benzamides}, volume={1371}, ISSN={0022-2860}, url={http://dx.doi.org/10.1016/j.molstruc.2026.146455}, DOI={10.1016/j.molstruc.2026.146455}, journal={Journal of Molecular Structure}, publisher={Elsevier BV}, author={Vairoletti, Franco and Rodríguez, Paulina and Cantero, Jorge and Paulino, Margot and Alvarez, Natalia and Ellena, Javier and Salinas, Gustavo and Dossi, Gonzalo Hernández and Mahler, Graciela and Saiz, Cecilia}, year={2026}, month=Oct, pages={146455} }