1: 53 percent / K2CO3 / acetonitrile / 48 h / Heating 2: 61 percent / (n-Bu4N)2Ce(NO3)6 / acetonitrile / 18 h / 25 °C 3: 28 percent / HCOONH4 / Pd/C / methanol / 0.17 h / Heating View Scheme

trifluoroacetic acid in acetonitrile T=70°C;

trifluoroacetic acid in tetrahydrofuran; water T=70°C;