1: triethylamine / 1-methyl-pyrrolidin-2-one / 30 - 90 °C / Inert atmosphere 2: sodium nitrite; acetic acid / toluene; water / 25 - 30 °C 3: potassium carbonate / toluene; water / 25 - 30 °C 4: hydrogenchloride; water / toluene; methanol / 0 - 20 °C View Scheme