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

A metabolite of the insecticide/acaricide etoxazole, designated R4 {systematic name N -[1-(4- tert -butyl-2-ethoxyphenyl)-2-hydroxyethyl]-2,6-difluorobenzamide, C 21 H 25 F 2 NO 3 }, is presented. The molecular structure has a central N -(2-hydroxyethyl)formamide group flanked by 4- tert -butyl-2-ethoxyphenyl and 2,6-difluorophenyl-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- tert -butyl-2-ethoxyphenyl and 2,6-difluorophenyl rings at a dihedral angle of 70.66 (5)°. In the crystal, molecules are linked by a strong O—H—O hydrogen bond into chains that extend parallel to the a -axis. There are also weaker C—H—F and π-stacking [centroid–centroid distance = 4.266 (2) Å] interactions. A Hirshfeld surface analysis reveals that the intermolecular contacts are dominated by interactions 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%).