Bepotastine Besilate: C~27~H~31~ClN~2~O~6~S. Mw: 547.06. (1) Benzenesulfonic acid; 4-[4-[(S)-(4-chlorophenyl)-pyridin-2-ylmethoxy]piperidin-1-yl]butanoic acid; (2)(+)-4-[[(S)-p-chloro-α-2-pyridylbenzyl]oxy]-1-piperidine butyric acid monobenzenesulfonate. CAS-190786-44-8.