反应详情

A solution of 7-carbomethoxy-5-chlorobenzo[b]furan (6c) (3.02 g, 14.3 mmol) containing potassium hydroxide (3.22 g) in 100 ml of aqueous methanol (CH3OH/H2O=3/2) was stirred at room temperature overnight. The mixture was concentrated under reduced pressure The residue was acidified with conc. HCl to pH of about 1, cooled in freezer for several hours and filtered to give 7c as an off-white solid (2.65 g, 94.3%), mp 212°-215° C. NMR (DMSO-d6) δ 8.0-6.87 (m, 5H, aromatic protons and OH).

1. concentrationThe mixture was concentrated under reduced pressure The residue
2. temperaturecooled in freezer for several hours
3. filtrationfiltered