Lux i cellulose 5 column

HPLC for obtaining the sulfoxide enantiomers was performed on a Shimadzu instrument composed of LC-10AT and LC-10AS pumps, a SPD-10A UV-VIS detector, a SIL-10A auto injector, a DGU-20A3R degassing unit, a CTO-20AC temperature controller and a SCL-10A system controller (Duisburg, Germany). The LCsolution software was used for instrument control and data acquisition. A Lux i-Cellulose 5 column (150 × 4.6 mm, 5 µm, Phenomenex, Aschaffenburg, Germany) containing cellulose tris(3,5-dichlorophenylcarabamate) as chiral selector in combination with methanol as mobile phase was used. The flow rate was 1.0 mL/min, the temperature was set at 20 °C and detection was carried out at 254 nm. 50 µL of the solutions of the sulfoxides prepared at a concentration of 1,2 mg/mL in methanol, were injected. A minimum of 20 runs were performed for each sulfoxide and the eluate containing the respective enantiomers were pooled followed by evaporation of the solvent under reduced pressure. The compounds were obtained as amorphous off-white to yellow solids. The purity of the isolated enantiomers was estimated by HPLC analysis using the same experimental set-up. The optical rotation of the purified enantiomers was determined in ethanol using a P2000 polarimeter from Jasco (Pfungstadt, Germany).