[OH:1][C:2]1[C:11]([CH3:12])=[C:10]2[C:5]([C:6]([CH3:14])=[CH:7][C:8](=[O:13])[O:9]2)=[CH:4][CH:3]=1.C([O-])([O-])=O.[K+].[K+].[CH2:21](Br)[CH:22]=[CH2:23]>CC(C)=O>[CH2:23]([O:1][C:2]1[C:11]([CH3:12])=[C:10]2[C:5]([C:6]([CH3:14])=[CH:7][C:8](=[O:13])[O:9]2)=[CH:4][CH:3]=1)[CH:22]=[CH2:21]7-Hydroxy-4,8-dimethylcoumarin (91.075 g, 0.479 mol), anhydrous K2CO3 (302.9 g, 2.190 mol), and allyl bromide (217.1 mL, 2.51 mol) were added to 2.5 L of reagent grade acetone. The milky mixture was refluxed for eight hours with overhead stirring, filtered, and the filtrate was concentrated to dryness with the rotary evaporator to obtain 7-allyloxy-4,8-dimethylcoumarin (113.5 g, 0.493 mol, 103%). The crude product melted at 94.0°-100° C. (lit. mp 108° C.) and was used in the next step.
Wird geladen…
