1-ethyl-1,4-dihydro-7-<1-(2-hydroxyethyl)-1H-pyrazol-4-yl>-4-oxo-1,8-naphthyridine-3-carboxylic acid, methyl ester 、 alkaline earth salt of/the/ methylsulfuric acid 反应 2.0h,
以83%的产率得到1-ethyl-1,4-dihydro-7-<1-(2-hydroxyethyl)-1H-pyrazol-4-yl>-4-oxo-1,8-naphthyridine-3-carboxylic acid