6-Chlorooxazolo[4,5-b]pyridin-2(3H)-one

6-Chloroxazolpyridinone is a key intermediate of the anticancer drug clotozantinib. Clozotinib is a targeted therapy drug developed by Pfizer Pharmaceuticals in the United States for non-small cell lung cancer. It is a cutting-edge and epoch-making drug in the field of targeted therapy for lung cancer. It was approved for sale in the United States in August 2011 and was included in the international lung cancer treatment guidelines at the end of the year as a first-line medication for ALK positive patients.