Synthesis of Angiotensin II Receptor Blockers by Means of a Catalytic System for C-H Activation

A highly efficient catalytic system for C-H activation has been worked out that involves inexpensive RuCl3.xH(2)O and a specific amount of PPh3. This procedure has been successfully applied to a practical synthesis of angiotensin II receptor blockers (ARBs). The residual ruthenium that existed in the reaction mixture was thoroughly removed by treatment with properly selected metal scavengers. The new process permits ready access to the important class of drugs in a highly atom-economical and sustainable manner.