反应详情

5-{1′-tert-butoxycarbonyl-4-oxospiro[chroman-2,4′-piperidin]-6-yl}nicotinic acid tert-butyl ester (14.0 g, 28.3 mmol) was dissolved in CHCl3 (70 mL) and 4N HCl in dioxane (210 mL) was added thereto, and stirred at room temperature for 20 h. The resulted precipitate was filtered and washed with CHCl3 and Et2O to afford 5-{4-oxospiro[chroman-2,4′-piperidin]-6-yl}nicotinic acid di-hydrochloride as a colorless solid.

1. filtrationThe resulted precipitate was filtered
2. washwashed with CHCl3 and Et2O