potassium carbonate in N,N-dimethyl-formamide T=30°C; 2 h;

1: 1.) NaOH / 1.) ethanol, 70 deg C, 30 min, 2.) ethanol, reflux, 4 h 2: 76.8 percent / SOCl2 / toluene / 1 h / 90 °C 3: 1.) 60percent NaH / 1.) DMF, 80 deg C, 30 min, 2.) DMF, 100 deg C, 4 h 4: KOH, H2O / ethanol / 3 h / Ambient temperature 5: 19.9 g / piperidine / pyridine / 4 h / 65 °C 6: KOH, H2O / ethanol / 8 h / Ambient temperature 7: 87.3 percent / aq. K2CO3 / dimethylformamide / 2 h / 30 °C View Scheme

1: 76.8 percent / SOCl2 / toluene / 1 h / 90 °C 2: 1.) 60percent NaH / 1.) DMF, 80 deg C, 30 min, 2.) DMF, 100 deg C, 4 h 3: KOH, H2O / ethanol / 3 h / Ambient temperature 4: 19.9 g / piperidine / pyridine / 4 h / 65 °C 5: KOH, H2O / ethanol / 8 h / Ambient temperature 6: 87.3 percent / aq. K2CO3 / dimethylformamide / 2 h / 30 °C View Scheme