hydrogen; acetic acid; palladium on activated charcoal in ethanol T=40 - 45°C; atmospheric pressure;

1: 4-methylene-oxetan-2-one With 4-(N,N-dimethlyamino)pyridine; polystyrene Wang resin in dichloromethane T=20°C; 18 h; 2: benzaldehyde; urea With hydrogenchloride in 1,4-dioxane T=70°C; Biginelli reaction; 18 h; 3: With trifluoroacetic acid in dichloromethane T=20°C; 0.5 h;

sodium hydroxide in ethanol; water 1 h; Heating;

sodium hydroxide in methanol 1 h; Heating;

1: hydrogenchloride / water; methanol / 40 °C 2: hydrogen; palladium 10 on activated carbon / methanol / 3.5 h / 20 °C View Scheme

Multistep reaction;