1: K2CO3 2: H2 / Pd-C View Scheme

potassium carbonate

1: 1.3 kg / bromine, sodium acetate / acetic acid / 45 h 2: 76 percent / copper / pyridine / 16 h / 95 °C 3: 1.04 kg / K2CO3 / dimethylformamide / 75 °C 4: 1.45 kg / 3-ethyl-5-(2-hydroxyethyl)-4-methylthiazolium bromide (ETB), triethylamine / 2 h / 90 °C 5: 65 percent / 3-chloroperbenzoic acid / CH2Cl2 / 2 h / Ambient temperature 6: 73 percent / lithium aluminium hydride, (S)-(-)-binaphthol / ethanol; tetrahydrofuran / 1.5 h 7: 55 percent / NaBH4 / CH2Cl2; ethanol / 1 h / Ambient temperature 8: 1.) lithium bis(trimethylsilyl)amide / 1.) THF, -78 deg C, 20 min, 2.) THF, 20 min 9: 100 percent / H2 / 10percent Pd/C / ethyl acetate / 1.5 h / 2068.6 Torr 10: 90 percent / potassium carbonate / acetone / 42 h / 56 °C View Scheme

1: 3,4-dihydroxy-benzaldehyde With sodium hydride in N,N-dimethyl-formamide; mineral oil T=20°C; 1 h; Inert atmosphereCooling with ice; 2: benzyl chloride in N,N-dimethyl-formamide; mineral oil T=20°C; 18 h; Inert atmosphereCooling with ice;

water; acetic acid T=150°C; 48 h; Heating / reflux;

1: 3,4-dihydroxy-benzaldehyde With sodium hydride in dimethyl sulfoxide T=20°C; 0.5 h; Inert atmosphere; 2: benzyl bromide in dimethyl sulfoxide Inert atmosphere;

1: 3,4-dihydroxy-benzaldehyde With sodium hydride in N,N-dimethyl-formamide; mineral oil T=0°C; 0.5 h; Inert atmosphere; 2: benzyl chloride in N,N-dimethyl-formamide; mineral oil T=0°C; 12 h;

N,N,N',N',N'',N''-hexamethylphosphoric triamide; sodium hydride; para-thiocresol in 1,1-dimethylpropan-1-ol; mineral oil T=20°C; 16 h; Inert atmosphereReflux;

potassium carbonate in N,N-dimethyl-formamide T=20 - 60°C; 16 h;

potassium carbonate in N,N-dimethyl-formamide T=80°C; 24 h;