in tetrahydrofuran; toluene T=20°C; 2 h;

1: methyl 3-amino-5-(4’-bromophenyl)thiophene-2-carboxylate With potassium hydroxide in ethanol; water 1 h; microwave irradiation; 2: phosgene in ethanol; water T=0 - 20°C;

1: sodium; methanol / 0.5 h / |Reflux 2: potassium hydroxide / methanol; water / 3 h / |Reflux 3: tetrahydrofuran; toluene / 2 h / 20 °C View Scheme

1.1: trichlorophosphate / 0.25 h / 25 °C 1.2: 0.5 h / 20 - 60 °C 1.3: 0.5 h 2.1: sodium; methanol / 0.5 h / |Reflux 3.1: potassium hydroxide / methanol; water / 3 h / |Reflux 4.1: tetrahydrofuran; toluene / 2 h / 20 °C View Scheme

1: potassium hydroxide / methanol; water / 3 h / |Reflux 2: tetrahydrofuran; toluene / 2 h / 20 °C View Scheme