1: With potassium tert-butylate in toluene T=60°C; 25 h; 2: With hydrogenchloride; water; acetic acid T=85°C; 4 h; 3: With sodium hydroxide in water T=20°C; pH=10;

PPA T=80 - 100°C; detosylation; 1.5 h;

2.1: NaH / dimethylformamide / 0.5 h / 20 °C 2.2: 64 percent / dimethylformamide / 5 h / 90 °C 3.1: tBuOK / toluene / 1 h / Heating 4.1: 7.3 g / aq. HCl / acetic acid; ethanol / 16 h / Heating 5.1: 77 percent / CF3COOH; CF3SO3H / methoxybenzene / 2 h / 20 °C View Scheme

1.1: NaH / dimethylformamide / 0.5 h / 20 °C 1.2: 64 percent / dimethylformamide / 5 h / 90 °C 2.1: tBuOK / toluene / 1 h / Heating 3.1: 7.3 g / aq. HCl / acetic acid; ethanol / 16 h / Heating 4.1: 77 percent / CF3COOH; CF3SO3H / methoxybenzene / 2 h / 20 °C View Scheme

1: tBuOK / toluene / 1 h / Heating 2: 7.3 g / aq. HCl / acetic acid; ethanol / 16 h / Heating 3: 77 percent / CF3COOH; CF3SO3H / methoxybenzene / 2 h / 20 °C View Scheme

1: 7.3 g / aq. HCl / acetic acid; ethanol / 16 h / Heating 2: 77 percent / CF3COOH; CF3SO3H / methoxybenzene / 2 h / 20 °C View Scheme

1.1: 100 percent / K2CO3 / acetone / 0.5 h / Heating 2.1: SnCl2*2H2O; conc. HCl / ethanol / 20 °C 3.1: 95 percent / pyridine / 20 °C 4.1: 100 percent / K2CO3 / dimethylformamide / 4 h / 120 °C 5.1: t-BuOK / toluene / 0.5 h / Heating 5.2: 51 percent / conc. HCl / acetic acid / 5 h / Heating 6.1: 82 percent / polyphosphoric acid / 1.5 h / 80 - 100 °C View Scheme

1.1: SnCl2*2H2O; conc. HCl / ethanol / 20 °C 2.1: 95 percent / pyridine / 20 °C 3.1: 100 percent / K2CO3 / dimethylformamide / 4 h / 120 °C 4.1: t-BuOK / toluene / 0.5 h / Heating 4.2: 51 percent / conc. HCl / acetic acid / 5 h / Heating 5.1: 82 percent / polyphosphoric acid / 1.5 h / 80 - 100 °C View Scheme

4-(N,N-dimethlyamino)pyridine; N-ethyl-N,N-diisopropylamine in dichloromethane T=20°C; 24 h;