4-Bromomethyl-7-acetoxycoumarin → 4-Bromomethyl-7-hydroxycoumarin

Participants

Reaction Steps

NaOMe (5.38 mL, 0.5 M, 2.69 mmol) was added slowly under argon to a stirred solution of 4-bromomethyl-7-acetoxycoumarin 6 (0.80 g, 2.69 mmol) in dry methanol (15 mL). The resulting mixture was stirred for 0.5 h. The methanolic solution was acidified with Dowex 50WX8 (H+) resin, filtered, washed with methanol, and evaporated to afford 7 as a white solid (0.68 g, 100%). TLC (hexane/ethyl acetate, 1:3): Rf=0.58. mp 207° C. 1H NMR (CD3OD, 500 MHz) δ 4.66 (s, 2H, CH2), 6.36 (s, 1H, C═CH), 6.73 (d, J=1.5 Hz, 1H), 6.84 (dd, J=1.5, 8.5 Hz, 1H), 7.71 (d, J=8.5 Hz, 1H). 13C NMR (CD3OD, 125 MHz) δ 27.58, 103.80, 111.17, 112.32, 114.37, 127.54, 153.61, 157.23, 163.24, 163.28. ESIMS calcd for C10H8BrO3 [M+H]+ 255.0. Found 255.1.

Provenance & Evidence