Construction of Amino‐Functionalized Molecularly Imprinted Silica Particles for (±)‐Ofloxacin Chiral Separation

Abstract

To enantioselectively separate a (±)‐ofloxacin (OFX) racemic mixture, we describe the production and successful use of an S‐ofloxacin (S‐OFX) enantio‐selective sorbent with amino functional groups. An amide derivative was first synthesized by reacting the S‐OFX enantiomer with 3‐aminopropyltriethoxysilane (S‐OFX‐Si‐NH 2 ). The generated S‐OFX‐Si‐NH 2 derivative was then mixed with tetraethoxysilane (TEOS) and put through a base‐catalyzed sol‐gel condensation polymerization process to insert the S‐OFX enantiomeric species into the cross‐linked material. To facilitate recombination involving S‐OFX, an enantioselective gap is created by alkaline hydrolysis followed by acidification, freeing the S‐OFX from the crosslinked matrix and filling the resulting gaps with cationic ions compatible with the S‐OFX. Our chemical transformations of the monomeric precursor and the ensuing S‐OFX molecularly imprinted material (S‐OFX‐Sil) were confirmed by elemental analysis, nuclear magnetic resonance (NMR), and Fourier transform infrared spectroscopy (FTIR). In addition, scanning electron microscopy images of the sorbent surface were employed to comprehend the morphological adjustments. Both the first loading run (60 % ee of R‐OFX) and the second elution run (83 % ee of S‐OFX) using the manufactured adsorbent particles showed promising separation results.