An improved process of pefloxacin mesylate from 1 ethyl 6 fluoro 1,4 dihydro 4 oxoquinoline 3 carboxlic acid was reported.

• 以1乙基6氟7氯1,4二氢4氧代喹啉3羧酸为原料,经甲哌嗪化,甲磺酸成盐得甲磺酸培氟沙星,总收率为826%25。