反应详情

A solution of ethyl 7-hydroxy-4-oxo-4H-1-benzopyran-2-carboxylate (19.0 g, 0.081 mol) in acetic acid is hydrogenated over 10% Pd/C (4.5 g) at 50 psi H2 for 16 hr at ambient temperatures. The catalyst is removed by filtration and the filtrate is concentrated in vacuo to give a residue. The residue is dissolved in EtOAc, washed with saturated NaHCO3, dried over Na2SO4 and concentrated in vacuo to give a solid residue. Crystallization of the solid from CCl4 affords the title compound as an off-white solid, 17.2 g (96% yield), mp 78-80° C., identified by NMR and mass spectral analyses.

1. customThe catalyst is removed by filtration
2. concentrationthe filtrate is concentrated in vacuo
3. customto give a residue
4. washwashed with saturated NaHCO3
5. dry with materialdried over Na2SO4
6. concentrationconcentrated in vacuo
7. customto give a solid residue
8. customCrystallization of the solid from CCl4