Monitoring the On‐line Titration of Enantiomeric Omeprazole Employing Continuous‐flow Capillary Microcoil 1H NMR Spectroscopy

The titration of the (S)‐enantiomer of omeprazole with the (R)‐enantiomer in chloroform‐d₁ is monitored by continuous‐flow capillary microcoil ¹H NMR spectroscopy employing a microcoil with a detection volume of 1.5 µl. The observed changes of the ¹H NMR chemical shifts indicate the formation of a heterochiral (R,S) dimer of omeprazole via its sulfinyl group and the NH group of the benzimidazole ring. Chirality 24:1074–1076, 2012. © 2012 Wiley Periodicals, Inc.