1-(3,4-Difluoro-benzyl)-4-hydroxy-2-oxo-2H-quinolizine-3-carboxylic acid ethyl ester 在
polyphosphoric acid trimethylsilyl ester 作用下,
反应 3.0h,
以15%的产率得到N-{3-[1-(3,4-difluoro-benzyl)-4-hydroxy-2-oxo-2H-quinolizin-3-yl]-1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-7-yl}-methanesulfonamide