Synthesis of [$^2$H$_5$]baricitinib via [$^2$H$_5$]ethanesulfonyl chlorideJansen-van Vuuren, Ross D. (Avtor) Vohra, Rahul (Avtor) baricitinibCOVID-19deuterationdeuterium-labelledSARS-CoV-2isotopologueBaricitinib, typically applied as a treatment for rheumatoid arthritis, has recently attracted the attention of clinicians and researchers as a potential treatment for COVID-19. Naturally, there has been a need for the preparation of the isotope-labelled analogue of baricitinib to probe the pharmacokinetics of baricitinib in this new role. As such, we have developed a simple synthetic route to deuterated [$^2$H$_5$]baricitinib, facilitating its formation over four steps and in a 29% overall yield based on starting [$^2$H$_5$]ethanethiol (19% if we start with [$^2$H$_5$]bromoethane instead). A critical component of the overall process involves the synthesis of [$^2$H$_5$]ethanesulfonyl chloride, and we describe in detail the two routes that were explored to optimize this step.20222022-05-27 15:57:15Članek v reviji136998sl