1: With piperidine; pyridine T=100°C; 6 h; 2: in water pH=3;

hydrogenchloride; malonic acid in pyridine

potassium acetate; sodium carbonate 1.) 160 deg C, 1 h; 170-180 deg C, 3 h, 2.) 3 h; Yield given. Multistep reaction;

1: 1-<3-(dimethylamino)propyl>-3-ethylcarbodiimide hydrochloride, 4-(N,N-dimethylamino)pyridine, imidazole / dimethylformamide / 3 h / Ambient temperature 2: 4 N aq. NaOH / methanol / 2 h / 60 °C View Scheme

sodium hydroxide; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride 1) dioxane, H2O, 2) dioxane, H2O, reflux; Multistep reaction;

1: 95 percent / HCO2NH4 / 10 percent Pd/C / ethanol / 16 h / 20 °C 2: 70 percent / methane sulfonic acid / 6 h / 95 °C View Scheme

hydrogen; palladium 10 on activated carbon in methanol; ethyl acetate P=1551.49 - 2068.65 Torr; 5 h;

1.1: 95 percent / HCO2NH4 / 10 percent Pd/C / ethanol / 16 h / 20 °C 2.1: 70 percent / methane sulfonic acid / 6 h / 95 °C 3.1: diethyl oxalate; NaOMe / toluene / 0 - 20 °C 3.2: 54 percent / KOH; aq. H2O2 / methanol / 19 h 4.1: 96.7 percent / acetic anhydride / toluene / 1 h / Heating View Scheme