sodium hydride in N,N-dimethyl-formamide T=60°C; 1 h;

1: diethyl ether / 34 °C 2: aq. HCl / ethanol / 80 °C 3: 88 percent / pyridine hydrobromide perbromide / CH2Cl2 / 0.5 h / 0 °C 4: 1.) ZnCl2, 2.) Pd(PPh3)4 / 1.) THF, reflux, 30 min, 2.) THF, reflux, 4 h 5: 81 percent / pyridine hydrochloride / 4 h / Heating 6: 75 percent / NaH / dimethylformamide / 1 h / 60 °C View Scheme

1: 1.) n-BuLi / 1.) THF, hexane, -78 deg C, 5 min, 2.) THF, hexane, a) from -78 deg C to RT, b) reflux, 3 h 2: concd. HCl / ethanol / 3 h / Heating View Scheme

1: diethyl ether / 34 °C 2: aq. HCl / ethanol / 80 °C 3: 88 percent / pyridine hydrobromide perbromide / CH2Cl2 / 0.5 h / 0 °C 4: 1.) ZnCl2, 2.) Pd(PPh3)4 / 1.) THF, reflux, 30 min, 2.) THF, reflux, 4 h 5: 81 percent / pyridine hydrochloride / 4 h / Heating 6: 75 percent / NaH / dimethylformamide / 1 h / 60 °C View Scheme