1: 5-bromo-3-methoxytoluene With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: boric acid trimethyl ester in tetrahydrofuran; hexane T=-78 - 20°C; 1.5 h; 3: With hydrogenchloride; water more than 3 stages;

1: 5-bromo-3-methoxytoluene With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: boric acid trimethyl ester in tetrahydrofuran; hexane T=-78 - 20°C; 1.5 h; 3: hydrogenchloride; water in tetrahydrofuran; hexane pH=3; Cooling;

1.1: 87 percent / Br2; glacial acetic acid / methanol / 2 h / cooling 2.1: NaNO2; aq. HCl / acetic acid / 0.75 h / 0 °C 2.2: 85 percent / aq. hypophosphorous acid / 0 - 20 °C 3.1: n-BuLi / tetrahydrofuran; hexane / 2 h / -78 °C 3.2: tetrahydrofuran; hexane / -78 - 20 °C 4.1: 1.494 g / aq. HCl / tetrahydrofuran / 2 h / 20 °C View Scheme

1.1: NaNO2; aq. HCl / acetic acid / 0.75 h / 0 °C 1.2: 85 percent / aq. hypophosphorous acid / 0 - 20 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 2 h / -78 °C 2.2: tetrahydrofuran; hexane / -78 - 20 °C 3.1: 1.494 g / aq. HCl / tetrahydrofuran / 2 h / 20 °C View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / 2 h / -78 °C 1.2: tetrahydrofuran; hexane / -78 - 20 °C 2.1: 1.494 g / aq. HCl / tetrahydrofuran / 2 h / 20 °C View Scheme