1: 1-(4-nitrophenyl)piperidin-2-one With phosphorus pentachloride in chloroform 2 h; Heating; 2: morpholine T=130°C; 1 h; Further stages.;

triethylamine in tetrahydrofuran 46 h; Inert atmosphereReflux;

1: triethylamine / tetrahydrofuran / 5 h / 5 - 20 °C / |Inert atmosphere 2: potassium tert-butylate / tetrahydrofuran / 2.5 h / 5 - 20 °C / |Inert atmosphere 3: phosphorus pentachloride / chloroform / |Reflux 4: 1 h / |Reflux View Scheme

1: triethylamine / tetrahydrofuran / 5 h / 5 - 20 °C / |Inert atmosphere 2: potassium tert-butylate / tetrahydrofuran / 2.5 h / 5 - 20 °C / |Inert atmosphere 3: phosphorus pentachloride / chloroform / |Reflux 4: 1 h / |Reflux View Scheme

1: potassium tert-butylate / tetrahydrofuran / 2.5 h / 5 - 20 °C / |Inert atmosphere 2: phosphorus pentachloride / chloroform / |Reflux 3: 1 h / |Reflux View Scheme

1: phosphorus pentachloride / chloroform / |Reflux 2: 1 h / |Reflux View Scheme

1: lithium carbonate / N,N-dimethyl-formamide / 5 h / 100 - 105 °C / |Inert atmosphere 2: triethylamine / tetrahydrofuran / 46 h / |Inert atmosphere; |Reflux View Scheme

1.1: water; Na2S*9H2O / ethanol / 4 h / 50 °C 2.1: triethylamine / tetrahydrofuran / 2 h / 5 - 50 °C / |Inert atmosphere 3.1: potassium tert-butylate / tetrahydrofuran / 8.5 h / 5 - 50 °C / |Inert atmosphere 4.1: potassium iodide; triethylamine / ethyl acetate / 6 h / |Reflux 4.2: 0 - 20 °C View Scheme

1: water; Na2S*9H2O / ethanol / 4 h / 50 °C 2: triethylamine / tetrahydrofuran / 2 h / 5 - 50 °C / |Inert atmosphere 3: potassium tert-butylate / tetrahydrofuran / 8.5 h / 5 - 50 °C / |Inert atmosphere View Scheme