sulfuric acid in water; N,N-dimethyl-formamide 0 deg C, RT, 30 min;

1: 70 percent / pyridine 2: 63 percent / KNH2 / dimethylformamide / RT, 100 deg C, 4 h 3: 77 percent / cc HCl / Ambient temperature 4: 40 percent / pyridine / 0 °C 5: 52 percent / 50percent H2SO4 / H2O; dimethylformamide / 0 deg C, RT, 30 min View Scheme

1: 63 percent / KNH2 / dimethylformamide / RT, 100 deg C, 4 h 2: 77 percent / cc HCl / Ambient temperature 3: 40 percent / pyridine / 0 °C 4: 52 percent / 50percent H2SO4 / H2O; dimethylformamide / 0 deg C, RT, 30 min View Scheme

1: 40 percent / pyridine / 0 °C 2: 52 percent / 50percent H2SO4 / H2O; dimethylformamide / 0 deg C, RT, 30 min View Scheme