triethylamine in benzene T=25°C; 6 h;

1: diethyl ether / 1 h / 25 °C 2: conc. aq. HCl / tetrahydrofuran / 1 h / Heating 3: aq. base / methanol / Heating 4: conc. aq. HCl / Heating View Scheme

hydrogenchloride Heating;