反应详情

A solution of 2-methylallyl 2,3-difluoro-6-hydroxy-5-(2-methylallyl)benzoate (734) in 96% formic acid (15 mL) was refluxed for 22 hours. The solvent was removed in vacuo, and the residue was purified by flash column chromatography eluting with hexanes-EtOAc (3:1) to afford 5,6-difluoro-2,2-dimethyl-3H-benzofuran-7-carboxylic acid (735) (0.76 g, 61%). 1H NMR (400 MHz, DMSO-d6) δ 7.43 (t, J=9.2 Hz, 1H), 2.98 (s, 2H), 1.41 (s, 6H).

1. customThe solvent was removed in vacuo
2. customthe residue was purified by flash column chromatography
3. washeluting with hexanes-EtOAc (3:1)