thionyl chloride in dichloromethane; N,N-dimethyl-formamide T=20°C; Inert atmosphere;

1: N,N-dimethyl-formamide / 120 °C 2: water; sulfuric acid / 4 h / 110 °C 3: thionyl chloride / 2 h / |Reflux View Scheme

1: water; sulfuric acid / 4 h / 110 °C 2: thionyl chloride / 2 h / |Reflux View Scheme

1: K2CO3 / CH2Cl2 / 20 °C 2: 86 percent / triethylsilane; PPh3 / Pd(OAc)2 / dimethylformamide / 12 h / 60 °C View Scheme

1: 46.5 g / pyridine / CH2Cl2 / 0 °C 2: 81 percent / p-toluenesulfonic acid monohydrate; p-xylene / 3 h / Heating 3: 93 percent / BBr3 / CH2Cl2 / -78 - 20 °C 4: 72 percent / dichlorobis(tri-o-tolylphosphine)palladium (II) / 1,2-diethoxy-ethane / 48 h / 115 °C View Scheme

ammonium hydroxide in dichloromethane T=0 - 20°C;

pyridine

pyridine