1: benzenesulphinic acid sodium salt With potassium carbonate in tetrahydrofuran 0.25 h; 2: 1-bromomethyl-3-methoxy-benzene in tetrahydrofuran T=0 - 67°C; 12 h;

CF3CO3H in trifluoroacetic acid T=30°C; 1.25 h;

dihydrogen peroxide in acetic acid

in N,N-dimethyl-formamide T=80°C;

1: 85 percent / PBr3 / benzene / a) 0 deg C, 1 h, b) from 60 to 75 deg C, 3 h 2: 87 percent / aq. NaOH, n-Bu4NBr / benzene / 0.5 h 3: 68 percent / acetic acid, conc. H2SO4, iodobenzene diacetate / 0.17 h / 0 °C 4: 38 percent / trifluoroperoxyacetic acid / trifluoroacetic acid / 1.25 h / 30 °C View Scheme

1: 87 percent / aq. NaOH, n-Bu4NBr / benzene / 0.5 h 2: 68 percent / acetic acid, conc. H2SO4, iodobenzene diacetate / 0.17 h / 0 °C 3: 38 percent / trifluoroperoxyacetic acid / trifluoroacetic acid / 1.25 h / 30 °C View Scheme

sodium ethanolate T=100°C; im Rohr;