N-ethyl-N,N-diisopropylamine in toluene T=60 - 75°C; 1 - 2 h;

in toluene; acetonitrile

1: 1.) n-BuLi, NaBr / 1.) THF, hexane, -40 deg C, 10 min, 2.) THF, hexane, -40 deg C, 30 min 2: 1.) POCl3, 2.) 50percent aq. NaOH / 1.) reflux, 3 h, 2.) 30 deg C, 2 h, pH 8 3: tetrahydrofuran / 0.5 h / 40 - 50 °C 4: 2 N aq. HCl / tetrahydrofuran / 1 h / 25 - 30 °C 5: 20 g / BF3 / 4 h / 120 °C 6: 42.4 g / toluene / 1 h / 80 °C View Scheme

1: tetrahydrofuran / 0.5 h / 40 - 50 °C 2: 2 N aq. HCl / tetrahydrofuran / 1 h / 25 - 30 °C 3: 20 g / BF3 / 4 h / 120 °C 4: 42.4 g / toluene / 1 h / 80 °C View Scheme

1: 1.) POCl3, 2.) 50percent aq. NaOH / 1.) reflux, 3 h, 2.) 30 deg C, 2 h, pH 8 2: tetrahydrofuran / 0.5 h / 40 - 50 °C 3: 2 N aq. HCl / tetrahydrofuran / 1 h / 25 - 30 °C 4: 20 g / BF3 / 4 h / 120 °C 5: 42.4 g / toluene / 1 h / 80 °C View Scheme

1: tetrahydrofuran / 0.5 h / 40 - 50 °C 2: 2 N aq. HCl / tetrahydrofuran / 1 h / 25 - 30 °C 3: 20 g / BF3 / 4 h / 120 °C 4: 42.4 g / toluene / 1 h / 80 °C View Scheme

in toluene; acetonitrile

1: 97 percent / conc. H2SO4 / 0.5 h / 75 °C 2: 1.) n-BuLi, NaBr / 1.) THF, hexane, -40 deg C, 10 min, 2.) THF, hexane, -40 deg C, 30 min 3: 1.) POCl3, 2.) 50percent aq. NaOH / 1.) reflux, 3 h, 2.) 30 deg C, 2 h, pH 8 4: tetrahydrofuran / 0.5 h / 40 - 50 °C 5: 2 N aq. HCl / tetrahydrofuran / 1 h / 25 - 30 °C 6: 20 g / BF3 / 4 h / 120 °C 7: 42.4 g / toluene / 1 h / 80 °C View Scheme

1: 20 g / BF3 / 4 h / 120 °C 2: 42.4 g / toluene / 1 h / 80 °C View Scheme

1: CF3SO3H / Heating 2: Et3N / toluene / Heating View Scheme