反应详情

The compound (1.86 g) obtained in Example 5 was dissolved in formic acid (7.5 mL) and 8.51 M hydrogen chloride—2-propanol solution (1.98 mL) was added under ice-cooling. The mixture was stirred at the same temperature for 20 min. Diethyl ether (50 mL) was added, and the precipitated crystals were collected by filtration to give the title compound as crystals (1.34 g).

1. temperaturecooling
2. filtrationthe precipitated crystals were collected by filtration