n-butyllithium; diisobutylaluminium hydride; tert-butyl alcohol in tetrahydrofuran; hexane T=0°C;

nitronium tetrafluoroborate in acetonitrile

methanol; hydrazine hydrate

1: 5-bromo-thiophene-2-carboxylic acid ethyl ester With diisobutyl-aluminum chloride in tetrahydrofuran T=-78°C; Inert atmosphereSchlenk technique; 2: With n-butyllithium in tetrahydrofuran; hexane T=-78 - 20°C; Inert atmosphereSchlenk technique; 3: 2-thiophenoyl chloride With CuCN*2LiCl in tetrahydrofuran; hexane T=-40 - 25°C; Inert atmosphere;

potassium hydroxide in ethanol Heating;

1: potassium fluoride / palladium diacetate / ethanol / 2 h / 110 °C / Microwave irradiation 2: sodium hydroxide; ethanol / 4 h / 70 °C View Scheme

sodium carbonate; tetrakis(triphenylphosphine) palladium(0) in ethanol; toluene T=80°C; 3 h;

1: aq. KOH / ethanol / Heating 2: SOCl2; pyridine / toluene / Heating View Scheme

sodium hydrogencarbonate; tetrakis(triphenylphosphine) palladium(0) in water; N,N-dimethyl-formamide T=100°C; 18 h;

1: CuI, (Ph3P)2PdCl2 / diethylamine / Ambient temperature 2: H2 / 5percent Pd-C / ethanol / 3.5 h / 2327.2 Torr 3: 98 percent / p-toluenesulfonic acid monohydrate, EtOH / 3 h / 65 °C 4: triethylamine, 4-(dimethylamino)pyridine / CH2Cl2 / 1.) 0 deg C, 30 min, 2.) RT, 18 h 5: 94 percent / Et3N / CH2Cl2 / 0.5 h / 0 °C 6: 64 percent / tetrabutylammonium fluoride / tetrahydrofuran / 1.5 h / Ambient temperature 7: 82 percent / NaH / tetrahydrofuran / 120 h 8: 79 percent / Mg(ClO4)2, NaN3 / acetonitrile / 36 h / 75 °C 9: H2 / 5percent Pd-C / tetrahydrofuran / 2 h / 1551.4 - 2327.2 Torr 10: Et3N / CH2Cl2 / 0.5 h View Scheme