1: acetonitrile / 2 h / 120 °C 2: various solvent(s) / 0.42 h / 220 - 230 °C 3: pyridine / 3 h / 100 °C View Scheme

1: SOCl2 / toluene; dimethylformamide / 2 h / 130 °C 2: acetonitrile / 2 h / 120 °C 3: various solvent(s) / 0.42 h / 220 - 230 °C 4: pyridine / 3 h / 100 °C View Scheme

1: various solvent(s) / 0.42 h / 220 - 230 °C 2: pyridine / 3 h / 100 °C View Scheme

1: various solvent(s) / 1 h / 130 °C 2: SOCl2 / toluene; dimethylformamide / 2 h / 130 °C 3: acetonitrile / 2 h / 120 °C 4: various solvent(s) / 0.42 h / 220 - 230 °C 5: pyridine / 3 h / 100 °C View Scheme

pyridine T=100°C; 3 h;