Acetic acid (1R,2R,3S)-2,3,4-triacetoxy-1-{[(3,4-dimethyl-phenyl)-(2,6-dioxo-1,2,3,6-tetrahydro-pyrimidin-4-yl)-amino]-methyl}-butyl ester 在
氯化亚砜 作用下,
以
氯仿 为溶剂,
反应 2.0h,
以53.3%的产率得到4a-Chlor-7,8-dimethyl-2,4-dioxo-2,3,4,5-tetrahydro-pyrimido<5.4-b><1.4>benzothiazin-10-yl-D-ribityl-tetraacetat