PREPARATION OF MILLIGRAMS OF PURE ENANTIOMERS USING ANALYTICAL-SCALE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Pure enantiomers of an agrochemical process intermediate, ,4-dimethyl- 2-(1H-1,2,4-triazol-1-yl)-pentan-3-one (1), have been prepared on the milligram scale under overload chromatographic conditions on an analyt ical chiral column (250 x 4.6 mm i.d.). The effects of variation of te mperature and mobile phase composition on retention factor, separation factor, and peak resolution have been investigated. Effects,of now ra te, enantiomer ratio, sample concentration, and column load on product ivity are also studied. Seven milligrams of the less retained (+)-enan tiomer and 5 mg of the (-)-enantiomer were obtained from a single inje ction of 21 mg of (RS)-1. (C) 1994 Wiley-Liss, Inc.