1: pyridine / 8 h / 20 °C 2: 15 g / AcOH; H2SO4 / 0 - 20 °C View Scheme

1: pyridine / 8 h / 20 °C 2: 15 g / AcOH; H2SO4 / 0 - 20 °C View Scheme

1.1: lithium carbonate / 0.5 h / 20 °C 1.2: 5 h / 30 - 100 °C 2.1: sulfuric acid / 1 h / 20 - 25 °C 2.2: 3 h / 20 °C View Scheme

T=20 - 60°C; 4 h;

1: pyridine / 1.) room temperature, 8 h, 2.) 45 deg C, 1.5 h 2: AcOH, H2SO4 / 0 °C 3: 1.) HCl gas, AcCl, 2.) H2O / 1.) CH2Cl2, 0 deg C, 12 h, 2.) MeCN, 0 deg C, 30 min View Scheme

1: pyridine / 1.) room temperature, 8 h, 2.) 45 deg C, 1.5 h 2: AcOH, H2SO4 / 0 °C 3: 1.) HCl gas, AcCl, 2.) H2O / 1.) CH2Cl2, 0 deg C, 12 h, 2.) MeCN, 0 deg C, 30 min 4: 1.) SO2Cl2 / 1.) CH2Cl2, DMF, room temperature, 3 h, 2.) room temperature, 20 h 5: 1.) Et3N*3HF, 2.) Et3N / 1.) EtOAc, 80 deg C, 3 h, 2.) 80 deg C, 1 h View Scheme

Multi-step reaction with 3 steps 1.1: lithium carbonate / 0.5 h / 20 °C1.2: 5 h / 30 - 100 °C2.1: sulfuric acid / 1 h / 20 - 25 °C2.2: 3 h / 20 °C3.1: trifluorormethanesulfonic acid / methyl acetate / 4 h / 90 - 115 °C / 22.5 Torr  

Multi-step reaction with 2 steps 1: pyridine / 8 h / 20 °C2: 15 g / AcOH; H2SO4 / 0 - 20 °C