反应详情

To a stirred solution of ethyl 8-bromo-7-(4-(tert-butoxycarbonyl)phenoxy)-6-chlorochroman-4-carboxylate (0.26 g, 0.51 mmol) in dichloromethane (5 mL) at ambient temperature was added trifluoroacetic acid (5 mL). The resulting solution was stirred at ambient temperature for 30 minutes. The solution was concentrated and the residual glassy solid was redissolved in ethyl acetate (2 mL). Hexanes (10 mL) were added, and after mixing for a few minutes, the product solidified. The mixture was concentrated to afford 4-(8-bromo-6-chloro-4-(ethoxycarbonyl)chroman-7-yloxy)benzoic acid as a light brown powder (0.23 g, 99% yield).

1. concentrationThe solution was concentrated
2. dissolutionthe residual glassy solid was redissolved in ethyl acetate (2 mL)
3. additionHexanes (10 mL) were added
4. additionafter mixing for a few minutes
5. concentrationThe mixture was concentrated