Enantiomeric resolution of propranolol and analogs on two cellulose (Chiralcel OF and OC) and one amylose (Chiralpak AD) chiral stationary phases

The enantiomeric chiral separation of propranolol and several aryloxyaminopropan-2-ol analogs is studied using two cellulose-type chiral stationary phases (CSPs) namely Chiralcel OF and Chiralcel OC and one amylose type chiral stationary phase (CSP), Chiralpak AD. The results showed base-line separation for all the compounds studied using amylose tris (3,5-dimethylphenyl carbamate) known as Chiralpak AD in comparison to the cellulose tris (4-chlorophenylcarbamate) known as Chiralcel OF which showed a significant decrease in the selectivities for most of the compounds, while partial or no separation were obtained using cellulose tris (phenylcarbamate) known as Chiralcel OC. It was observed that the chiral separation depends on the substitution pattern on the aryl group of the aryloxyaminopropan-2-ol i.e. 1-naphthyl, 2-naphthyl and phenyl group and the polarity on the basic nitrogen in the side chain which indicate that the substituents on the side chain did effect the interaction of the enantiomers with the polar carbamate moiety in the chiral stationary phase. Furthermore, the substituents on the phenylcarbamate group of the CSP does play a role in the enantiospecific recognition mechanisms.