LAUSR

Abstract A facile, universal and economical method was developed for the synthesis of polycyclic carbamyl pyridone analogues of Baloxavir marboxil from the cyclization of chloroacetaldehyde with o-aminoamide derivatives. In this method, without any other catalysts or additives, the polycyclic carbamoyl pyridone analogues can be obtained by ring closure of o-aminoamide derivatives and chloroacetaldehyde under the action of a base, and no harsh reaction conditions are required. The method operation is simple and suitable for industrial production. A series of polycyclic carbamyl pyridone analogues were prepared in moderate to excellent yields.