Method of producing (3S,11aR)-6,8-dihalo-3-methyl-2,3,11,11a-tetrahydrooxazolo3,2-apyrido1,2-dpyrazine-5,7-diones

摘要

A process for preparing a compound shown by formula (W6):; wherein each Hal is independently chloro or bromo, using a novel process for preparing a pyridine derivative represented by formula (W2), wherein R^6d is as defined herein.