the enantiomers of the benzothiadiazines penflutizide ( 2a ) and bendroflumethiazide ( 2b ) in high optical purity , as well as enriched ( + ) -buthiazide ( 2j ) were obtained by repeated chromatography on a semipreparative scale .
C0005084
benzothiadiazines
C0004975
bendroflumethiazide