Flash chiral chromatography with cellulose tris(3,5-dimethylphenylcarbamate)-coated phases Improved resolution of basic analytes

The preparative resolution of some chiral basic analytes on a flash chiral chromatography column packed with a cellulose carbamate-coated phase is described. Compared with separations obtained, on a column packed with 20% (w/w) cellulose tris(3,5-dimethylphenylcarbamate) coated onto underivatised flash silica (40-63 mu m Davisil, 150 Angstrom), a substantial improvement was observed when the support medium was changed to octadecylated silica (37-55 mu m Bondapak ODS, 300 Angstrom). The ODS phase is extremely effective for the preparative separation of basic analytes such as beta-blockers and the optimum conditions can be readily established by the use of a related high-pressure liquid chromatography column containing the chiral carbamate coated onto Nucleosil-ODS (5 mu m, 300 Angstrom).