1.1: diphenylether / 245 °C 2.1: oxalyl dichloride; N,N-dimethyl-formamide / 1,2-dichloro-ethane 3.1: n-butyllithium / tetrahydrofuran; hexane / 2 h / -70 °C / |Inert atmosphere; |Large scale 3.2: 19.3 h / -70 - 20 °C / |Inert atmosphere; |Large scale 4.1: tetrakis(triphenylphosphine) palladium(0) / N,N-dimethyl-formamide / 40 h / 95 °C / |Inert atmosphere; |Large scale View Scheme

1.1: diphenylether / 245 °C 2.1: oxalyl dichloride; N,N-dimethyl-formamide / 1,2-dichloro-ethane 3.1: n-butyllithium / tetrahydrofuran; hexane / 2 h / -70 °C / |Inert atmosphere; |Large scale 3.2: 19.3 h / -70 - 20 °C / |Inert atmosphere; |Large scale View Scheme

1: diphenylether / 0.5 h / 259 °C 2: oxalyl dichloride; N,N-dimethyl-formamide / dichloromethane; 1,2-dichloro-ethane / 6 h / |Reflux View Scheme

in diphenylether T=20 - 200°C;

1: 2,2-Dimethyl-[1,3]dioxane-4,6-dione; trimethyl orthoformate With potassium carbonate T=30°C; 1 h; 2: thiophen-3-ylamine T=20 - 85°C; 15 h; 3: With potassium carbonate in dichloromethane 0.5 h;

1: orthoformic acid triethyl ester; 3-aminothiophene oxalate 0.25 h; 2: 2,2-Dimethyl-[1,3]dioxane-4,6-dione T=85°C;