Intermolecular interactions responsible for the absence of chiral recognition: aromatic C–H ⋯ O hydrogen bonding in the crystal structure of 3-chloro-9,13-dibutylamino-1-hydroxypropyl-6-trifluomethylphenanthrene propan-2-ol solvate hydrochloride

Abstract

Both the 3-Cl and the more remote 6-CF₃ groups in 1-dechlorohalofantrine 3 promote strong edge-to-edge aromatic O ⋯ H(1)–C interactions, similar to those found in thiamine picrate 6, which we suggest inhibit the resolution of 3 on chiral HPLC columns, whereas the 1-Cl substituent in halofantrine itself 2 blocks this interaction and allows resolution via chiral π–π face stacking.