反应详情

The resulting monomethyl 2-[5-chloro-3-(2-ethoxypyridin-3-yl)-6-fluoro-2-oxo-2,3-dihydro-1H-indol-3-yl]malonate (4.58 g) was heated in a one-neck flask under a blanket of nitrogen to 150° C. During this, CO2 gas was evolved and methyl [5-chloro-3-(2-ethoxypyridin-3-yl)-6-fluoro-2-oxo-2,3-dihydro-1H-indol-3-yl]acetate was formed. The reaction mixture was cooled to room temperature, and the substance was mixed with methanol. The crystals which formed were stored in a refrigerator at 5° C. overnight. The solid was filtered off with suction and washed with a little methanol. 3.286 g (8.68 mmol, 80% yield) of the title compound were obtained as a white solid.