INTERMOLECULAR INTERACTIONS RESPONSIBLE FOR THE ABSENCE OF CHIRAL RECOGNITION - AROMATIC C-H...O HYDROGEN-BONDING IN THE CRYSTAL-STRUCTURE OF LAMINO-1-HYDROXYPROPYL-6-TRIFLUOMETHYLPHENANTHRENE PROPAN-2-OL SOLVATE HYDROCHLORIDE

Both the 3-Cl and the more remote 6-CF3 groups in 1-dechlorohalofantri ne 3 promote strong edge-to-edge aromatic O...H(1)-C interactions, sim ilar to those found in thiamine picrate 6, which we suggest inhibit th e resolution of 3 on chiral HPLC columns, whereas the 1-Cl substituent in halofantrine itself 2 blocks this interaction and allows resolutio n via chiral pi-pi face stacking.