1.1: n-butyllithium / tetrahydrofuran / 1 h / -78 °C / Inert atmosphere 1.2: 20 °C 2.1: water; lithium hydroxide hydrate / tetrahydrofuran; methanol / 2 h / 20 °C View Scheme

1: 1.) thiourea, I2, KI, 2.) 1.5 N aq. NaOH / 1.) MeOH, RT, 2 h, 2.) MeOH, 90 deg C, 30 min 2: NaOH / methanol; H2O; diethyl ether / 2 h / Ambient temperature 3: 1 M BF3*THF / tetrahydrofuran / 18 h / Ambient temperature View Scheme

1: 5-chloro-2-methyl-indole With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: With zinc(II) chloride in tetrahydrofuran; hexane T=-78 - 20°C; 3: 4-(4-bromo-butoxy)-benzoic acid methyl ester in tetrahydrofuran; hexane T=20°C;

1.1: n-butyllithium / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: zinc chloride / tetrahydrofuran; hexane / -78 - 20 °C 1.3: 46 percent / tetrahydrofuran; hexane / 20 °C 2.1: NaH / dimethylformamide / 0.5 h / 0 °C 2.2: 77 percent / dimethylformamide / 0 - 20 °C 3.1: 86 percent / aq. NaOH / tetrahydrofuran; methanol / 50 °C View Scheme

phosphoric acid in acetic acid

phosphoric acid; acetic acid T=80°C;

1: With trichlorophosphate T=10 - 50°C; 2: With sodium hydrogencarbonate in water T=60°C; 0.25 h;

trichlorophosphate in N,N-dimethyl-formamide