1: dimethylsulfoxide / 3 h / 80 °C 2: H2, Et3N / 10percent Pd/C / Ambient temperature 3: 1.) CF3COOH / 1.) 10 min, 2.) 0 deg C, 10 min View Scheme

1: H2, Et3N / 10percent Pd/C / Ambient temperature 2: 1.) CF3COOH / 1.) 10 min, 2.) 0 deg C, 10 min View Scheme

trifluoroacetic acid 1.) 10 min, 2.) 0 deg C, 10 min; Yield given. Multistep reaction;