Synthesis of N6-[endo-2′(endo-5′-hydroxy)norbornyl]-8-(N-methylisopropyl-amino)-9-methyladenine (WRC-0571):: A potent and selective adenosine A1 receptor antagonist

A new versatile synthesis of N-6-[endo-2'-(endo-5-hydroxy)norbomyl]-8-(N-methylisopropylamino)-9-methyladenine (WRC-0571), a highly potent and selective antagonist for adenosine A, receptor, is presented. The overall yield is 14%. The key step involved the stereoselective reduction of endo-2-(diphenylmethyl-amino)norboman-5-one to generate the endo-5-hydroxy substituent using the Luche reagent (NaBH4-CeCl3) at -40 degrees C.