1: 68 percent / aq. PPh3 / tetrahydrofuran / 24 h / 20 °C 2: 62 percent / NaHCO3 / methanol / 3 h / 20 °C 3: 89 percent / aq. TFA / 5 h / 20 °C 4: 45 percent / H2 / Pd/C / methanol / 24 h 5: H2 / Pd(OH)2/C / methanol / 24 h View Scheme