Synthesis of New Fatty N-Acylamino Amides from 3,4-Dichloroaniline with Crop Protection Activity

Abstract

A series of biologically active N-acylamino amides were synthesized from readily available amino acids and common fatty acids from oil seeds, including the pharmacophoric group in the family of herbicides propanil, linuron, and diuron. The esterification followed by N-acylation with long-chain fatty acids was carried out with O-(benzotriazole-1-yl)-N,N,N’,N’-tetramethyluronium tetrafluoroborate (TBTU) as activating agent. The N-acylamino esters were synthesized and isolated in good yields (70-98%), which after the hydrolysis step, provided the N-acylamino acids. Finally, new N-acylamino amides were obtained from the reaction with 3,4-dichloroaniline in the presence of TBTU and N,N-diisopropylethylamine (DIPEA), in yields between 24-83%. Bioassays were conducted against arthropod strawberry pests Chaetosiphon fragaefolii, Duponchelia fovealis, and Drosophila suzukii, without any registered compound for use in strawberry crops in Brazil. The bioassay studies showed promising results, with mortality percentages ranging from 20-80%, and the best relative mortality by N-oleyl glycinamide, suggesting a possible fatty chain-amino acid synergistic bioactivity. Overall, this study provides an efficient and sustainable method for synthesizing biologically active N-acylamino amides from abundant natural sources, with potential applications in the development of ecofriendly agrochemicals.