1: glac. acetic acid / ethanol / 6 h 2: 1) NaNO2, HCl / 1) gl. acetic acid, 0-5 deg C, 2) pyridine, rt View Scheme

1: 78 percent / conc. hydrochloric acid / ethanol / 2 h / 150 - 160 °C 2: glac. acetic acid / ethanol / 6 h 3: 1) NaNO2, HCl / 1) gl. acetic acid, 0-5 deg C, 2) pyridine, rt View Scheme

1: 1) acetic anhydride, piperidine, 2) water / 1) 130-145 deg C, 6 h 2) reflux, 30 min 2: 78 percent / conc. hydrochloric acid / ethanol / 2 h / 150 - 160 °C 3: glac. acetic acid / ethanol / 6 h 4: 1) NaNO2, HCl / 1) gl. acetic acid, 0-5 deg C, 2) pyridine, rt View Scheme

hydrogenchloride; sodium nitrite 1) gl. acetic acid, 0-5 deg C, 2) pyridine, rt; Multistep reaction;