silica-supported aluminum chloride T=60°C; Michael addition; 1.5 h; Neat (no solvent);

in 2,2,2-trifluoroethanol; water T=80°C; Aza-Michael reaction; 16 h;

1: pyridine / 0.33 h / Heating 2: aq. HCl / dioxane / 3 h / Heating 3: 1.) PCl5, 2.) AlCl3 / 1.) benzene, from 5 deg C to 23 deg C, 30 min, 2.) benzene 15-20 deg C, 3.5 h 4: gl. AcOH, aq. HCl / 3.5 h / Heating 5: 28 percent / conc. HCl / propan-2-ol / 17 h / Heating View Scheme

1: pyridine / 0.33 h / Heating 2: aq. HCl / dioxane / 3 h / Heating 3: 1.) PCl5, 2.) AlCl3 / 1.) benzene, from 5 deg C to 23 deg C, 30 min, 2.) benzene 15-20 deg C, 3.5 h 4: gl. AcOH, aq. HCl / 3.5 h / Heating View Scheme