in ethanol

piperidine in ethanol 5 h; Heating / reflux;

1.1: potassium carbonate / tert-butyl alcohol / 1.17 h / |Reflux 1.2: 11 h / |Reflux 2.1: thionyl chloride / chloroform / 1 h / |Reflux 3.1: acetic acid; piperidine / toluene / |Heating 4.1: zinc; acetic acid / methanol / 15 h / 25 - 30 °C View Scheme

1.1: N-bromosuccinmide / tert-butyl alcohol; water / 1.5 h / 25 °C / |Large scale 1.2: 0.75 h / |Large scale 1.3: PEG 4000 / 17 h / 78 °C / |Large scale 2.1: pyrrolidine / methanol / 2 h / 50 - 55 °C / |Large scale 3.1: thionyl chloride / chloroform / 3 h / |Reflux 4.1: zinc; acetic acid / methanol / 15 h / 25 - 30 °C View Scheme

1.1: thionyl chloride / chloroform / 2 h / |Reflux 2.1: zinc; acetic acid / 15 h / 25 - 30 °C 3.1: N-bromosuccinmide / tert-butyl alcohol; water / 1.5 h / 25 °C / |Large scale 3.2: 0.75 h / |Large scale 3.3: PEG 4000 / 17 h / 78 °C / |Large scale 4.1: thionyl chloride / chloroform / 1 h / |Reflux 5.1: acetic acid; piperidine / toluene / |Heating 6.1: zinc; acetic acid / methanol / 15 h / 25 - 30 °C View Scheme

1.1: zinc; acetic acid / 15 h / 25 - 30 °C 2.1: N-bromosuccinmide / tert-butyl alcohol; water / 1.5 h / 25 °C / |Large scale 2.2: 0.75 h / |Large scale 2.3: PEG 4000 / 17 h / 78 °C / |Large scale 3.1: pyrrolidine / methanol / 2 h / 50 - 55 °C / |Large scale 4.1: thionyl chloride / chloroform / 3 h / |Reflux 5.1: zinc; acetic acid / methanol / 15 h / 25 - 30 °C View Scheme

1.1: potassium carbonate / tert-butyl alcohol / 1.17 h / |Reflux 1.2: 11 h / |Reflux 2.1: thionyl chloride / chloroform / 1 h / |Reflux 3.1: acetic acid; piperidine / toluene / |Heating 4.1: zinc; acetic acid / methanol / 15 h / 25 - 30 °C View Scheme

1: dihydrogen peroxide / acetic acid / 14 h / 100 °C 2: 0.5 h / 120 °C 3: sodium hydroxide / water / 2 h / 40 °C 4: thionyl chloride; triethylamine / dichloromethane / 1.25 h / 0 - 5 °C 5: N,N-dimethyl-formamide / 14 h / 80 °C 6: pyrrolidine / methanol / 2 h / 50 - 55 °C / |Large scale 7: thionyl chloride / chloroform / 3 h / |Reflux 8: zinc; acetic acid / methanol / 15 h / 25 - 30 °C View Scheme

1: 0.5 h / 120 °C 2: sodium hydroxide / water / 2 h / 40 °C 3: thionyl chloride; triethylamine / dichloromethane / 1.25 h / 0 - 5 °C 4: N,N-dimethyl-formamide / 14 h / 80 °C 5: thionyl chloride / chloroform / 1 h / |Reflux 6: acetic acid; piperidine / toluene / |Heating 7: zinc; acetic acid / methanol / 15 h / 25 - 30 °C View Scheme

1: thionyl chloride / chloroform / 1 h / |Reflux 2: acetic acid; piperidine / toluene / |Heating 3: zinc; acetic acid / methanol / 15 h / 25 - 30 °C View Scheme