Separation of enantiomers of 2-(4-hydroxyphenoxy) propionates by high-performance liquid chromatography

The separation of enantiomers of (+/-)2-(4-hydroxyphenoxy)propionates, the intermediates for aryloxyphenoxypropionate herbicides, has been achieved by high-performance liquid chromatography on a chiral column. The experimenta l results showed that the enantiomers of the ethyl ester and methyl ester o f 2-(4-hydroxyphenoxy)propionic acid could be well separated on the tribenz oylcellulose (CTB) chiral column with ethanol as mobile phase. Their separa tion factors were 1.44 and 1.29 respectively. At the same time,it was found that the size of the ester group in the 2-substituted aryloxy or aryl prop ionates obviously affected the separation efficiency of their enantiomers o n the CTB chiral column. The separation of enanatiomers of the ethyl ester was most satisfactory. And, the order of elution has been proved that the ( +)-configuration of ethyl 2-(4-hydroxyphenoxy)propionate was eluted before the (-)-configuration by comparison experiment.