反应详情

温度

35 °C

85.3 mg of 4-(2-carbamoylethoxy)-3-[(E)-2-(4-fluorophenyl)-vinyl]-1H-indazole-5-carboxylic acid ethyl ester obtained by Example 763 was dissolved in 3 mL of concentrated sulfuric acid, stirred at 35° C. for 16 hours, and then added with ice under ice cooling. The precipitated crystals were collected by filtration, washed with water, and then dried under reduced pressure, to afford 43.7 mg of the title compound as yellow crude crystals.

1. additionadded with ice under ice cooling
2. filtrationThe precipitated crystals were collected by filtration
3. washwashed with water
4. customdried under reduced pressure