反应详情

In a solution of ethyl 8-(2-benzyloxymethyl-2,3-dihydrobenzofuran-5-carboxamido)-4-oxo-4H-1-benzopyran-2-carboxylate (528 mg, 1.06 mmol) in methanol (25 ml) and anhydrous tetrahydrofuran (25 ml), ammonia gas was bubbled for 30 minutes. After evaporation to dryness, the resulting solid residue was dissolved in a tetrahydrofuran:methanol 1:1 mixture (15 ml) and added with concentrated HCl (0.5 ml). The mixture was refluxed under stirring for 1.5 h, then the solvents were evaporated off under reduced pressure. The resulting crude was suspended in water and the insoluble solid was recovered by filtration, washed repeatedly with water and dried under vacuum on phosphorous pentoxyde, thereby obtaining 527 mg of the title compound (quantitative yield).

1. customAfter evaporation to dryness
2. dissolutionthe resulting solid residue was dissolved in a tetrahydrofuran:methanol 1:1 mixture (15 ml)
3. additionadded with concentrated HCl (0.5 ml)
4. temperatureThe mixture was refluxed
5. customthe solvents were evaporated off under reduced pressure
6. filtrationthe insoluble solid was recovered by filtration
7. washwashed repeatedly with water
8. customdried under vacuum on phosphorous pentoxyde