1: 80 percent / acetic anhydride / 2 h / Heating 2: 80 percent / 10percent aq. KOH / ethanol / 0.25 h View Scheme

1: 80 percent / acetic anhydride / 2 h / Heating 2: 80 percent / 10percent aq. KOH / ethanol / 0.25 h 3: H2 / 5percent Pd/carbon / acetic acid / 12 h 4: 70 percent / PPA / 4 h / 160 °C View Scheme

potassium hydroxide in N,N-dimethyl-formamide 2 h;