Crystal structure and Hirshfeld surface analysis of an etoxazole metabolite designated R4

A metabolite of the insecticide/acaricide etoxazole, designated <b>R4</b> {systematic name <i>N</i>-[1-(4-<i>tert</i>-butyl-2-eth-oxy-phen-yl)-2-hy-droxy-eth-yl]-2,6-di-fluoro-benz-amide, C₂₁H₂₅F₂NO₃}, is presented. The mol-ecular structure has a central <i>N</i>-(2-hy-droxy-ethyl)formamide group flanked by 4-<i>tert</i>-butyl-2-eth-oxy-phenyl and 2,6-di-fluoro-phenyl-substituted rings. The overall conformation is defined by its torsional degrees of freedom [N-C-C-C = 56.09 (18) and 99.41 (18)°], which place the 4-<i>tert</i>-butyl-2-eth-oxy-phenyl and 2,6-di-fluoro-phenyl rings at a dihedral angle of 70.66 (5)°. In the crystal, mol-ecules are linked by a strong O-H-O hydrogen bond into chains that extend parallel to the <i>a</i>-axis. There are also weaker C-H-F and π-stacking [centroid-centroid distance = 4.266 (2) Å] inter-actions. A Hirshfeld surface analysis reveals that the inter-molecular contacts are dominated by inter-actions involving hydrogen, the most abundant being H⋯H (54.1%), H⋯O/O⋯H (13.0%), H⋯F/F⋯H (12.8%), and H⋯C/C⋯H (12.8%).