hydrogen; palladium on activated charcoal in ethanol 12 h;

1: 95 percent / H2 / Pd/C / ethanol / 12 h 2: 59 percent / TFA, EDC / dimethylformamide / Ambient temperature 3: 77 percent / H2 / Pd/C / dimethylformamide / 6 h / Ambient temperature View Scheme