Benzo[1,3]dioxol-5-yl-(3-ethoxy-4-methoxy-phenyl)-methanol → Benzo[1,3]dioxol-5-yl-(3-ethoxy-4-methoxy-phenyl)-methanone
Reaktionsgleichung
[O:1]1[C:5]2[CH:6]=[CH:7][C:8]([CH:10]([C:12]3[CH:17]=[CH:16][C:15]([O:18][CH3:19])=[C:14]([O:20][CH2:21][CH3:22])[CH:13]=3)[OH:11])=[CH:9][C:4]=2[O:3][CH2:2]1>C(Cl)Cl.O=[Mn]=O>[O:1]1[C:5]2[CH:6]=[CH:7][C:8]([C:10]([C:12]3[CH:17]=[CH:16][C:15]([O:18][CH3:19])=[C:14]([O:20][CH2:21][CH3:22])[CH:13]=3)=[O:11])=[CH:9][C:4]=2[O:3][CH2:2]1Komponenten
4
Versuchsvorschrift
To a stirred solution of benzo[1,3]dioxol-5-yl-(3-ethoxy-4-methoxy-phenyl)-methanol (1.09 g, 3.6 mmol) in CH2Cl2 (20 mL) at room temperature was added activated MnO2 powder (1.6 g, 18.1 mmol) and kept adding 23 equivalents of MnO2 every 35 h until HPLC showed disappearance of the starting material. The black suspension was filtered through a Celite pad, concentrated in vacuo to give benzo[1,3]dioxol-5-yl-(3-ethoxy-4-methoxy-phenyl)-methanone as an off-white solid (1.06 g, 98% yield): 1H NMR (CDCl3) δ 1.49 (t, J=7 Hz, 3H, CH2CH3), 3.95 (s, 3H, OCH3), 4.16 (q, J=7 Hz, 2H, CH2CH3), 6.07 (s, 2H, CH2), 6.85-6.91 (m, 2H, Ar), 7.32-7.42 (m, 4H, Ar). The product was used in the next step without further purification.