Synthesis of doubly13C-labelled antalarmin isotopomers for pharmacokinetic studies

Abstract Antalarmin (butyl‐ethyl‐[2,5,6‐trimethyl‐7‐(2,4,6‐trimethyl‐phenyl)‐7 H ‐pyrrolo[2,3‐ d ]pyrimidin‐4‐yl]‐amine) was doubly labelled with carbon‐13. The synthesized butyl‐[ 13 C 2 ]ethyl‐[2,5,6‐trimethyl‐7‐(2,4,6‐trimethyl‐phenyl)‐7 H ‐pyrrolo[2,3‐ d ]pyrimidin‐4‐yl]‐amine ( 1 ) and butyl‐ethyl‐[2‐ 13 C]‐[2,5,6‐trimethyl‐7‐(2,4,6‐trimethyl‐phenyl)‐7 H ‐pyrrolo[2,3‐ d ]‐[2‐ 13 C] pyrimidin‐4‐yl]‐amine, ( 2 ) were prepared for use as substrates for pharmacokinetic studies. These compounds were obtained in fair overall yield in a 5 and 6 step synthesis (20–24.5%, respectively) and high isotopic purity (about 99 at% 13 C). Copyright © 2002 John Wiley & Sons, Ltd.