Synthesis of deuterium‐labeled zaleplon‐d5 as an internal standard

Abstract Zaleplon is licensed for the short‐term treatment of insomnia. Excessive usage causes side effects; hence, the drug is controlled. Identifying zaleplon in a drug abuser requires an isotope‐labeled internal standard. This work presents a synthesis of stable isotope‐labeled internal standard for zaleplon, zaleplon‐ d 5 , by a five‐step synthetic sequence. Copyright © 2008 John Wiley & Sons, Ltd.