A facile and expedient route for the synthesis of 2‐ethoxy‐ and 2‐(ethylcarboxylate)‐(4H)‐3,1‐benzoxazine‐4‐ones is described using guanidinium chloride as a safe and convenient dehydrocyclizationagent. High yields of the products obtain under mild reaction conditions without need to use of any catalyst and with easy work‐up of the reaction mixture.
The present invention relates to macrocyclic compounds of formula I that are useful as inhibitors of the hepatitis C virus (HCV) NS3 protease, their synthesis, and their use for treating or preventing HCV infections.