反应详情

A solution of 4,7-dihydroxycoumarin (1.78 g, 0.01 mole) in dry DMF (7.5 ml) was stirred during the addition of 100% sodium hydride (0.24 g, 0.01 mole) and the mixture stirred for 1 hour at 100°. A solution of benzyl chloride (1.27 g, 0.01 mole) in dry DMF (1 ml) was added dropwise and stirring continued at 100° for a further 4 hours. After removal of the solvent in vacuo water was added and the oily solid which precipitated was separated. Recrystallisation from ethanol gave 0.623 g (23%) of title compound of mp 234° νmax (mull) 3150, 3050, 1710, 1630 cm-1, τ(DMSO) 4.67 (2H, s); 4.19 (1H,s); 3.28 (1H near s); 3.20 (1H, d.d., J 2.0 Hz; 5.0 Hz) 2.66-2.26 (6H, m), 1 low field broad exchangeable proton. (Found, C, 71.51; H, 4.70; C16H12O4 requires; C , 71.63; H, 4.51%).

1. stirringstirring
2. waitcontinued at 100° for a further 4 hours
3. customAfter removal of the solvent in vacuo water
4. additionwas added
5. customthe oily solid which precipitated
6. customwas separated
7. customRecrystallisation from ethanol