Crystal structures and Hirshfeld surface analyses of two precursors of the etoxazole metabolite 'R8'.

Etoxazole is an agricultural pesticide that degrades into potentially haza-rdous metabolites, necessitating a thorough understanding of their chemical properties for accurate environmental and health risk assessments. This study reports the synthesis and structural characterization of two precursors of an etoxazole metabolite designated 'R8': 1-(4-tert-butyl-2-eth-oxy-phen-yl)-2-hy-droxy-ethan-1-one, C14H20O3 (I), and 1-(4-tert-butyl-2-eth-oxy-phen-yl)ethan-1-one, C14H20O2 (II). Compound I crystallizes with the symmetry of space group Pnma, while II crystallizes as P21/m. In both structures, the mol-ecules lie on crystallographic mirror planes (Z' = 1/2) and exhibit a high degree of conformational similarity, differing primarily in the torsion angle of the tert-butyl group. The crystal packing in both structures is consolidated by weak C-H⋯π contacts that assemble the mol-ecules into columns parallel to the crystallographic b axes. Hirshfeld-surface analyses show that the inter-molecular inter-actions in both compounds are overwhelmingly dominated by contacts involving hydrogen atoms.