1: 70 percent / Amberlite IRA-402 (HCO3-), H2O / 192 h / 3 - 4 °C 2: 69 percent / K2CO3 / dimethylformamide / Ambient temperature 3: H2 / Raney Ni / H2O / 1.5 h / 760 Torr / Ambient temperature 4: Et3N / methanol / 72 h / -18 °C 5: aq. acid / 25 °C / pH 3.34, var. pH, temp. View Scheme

1: 70 percent / Amberlite IRA-402 (HCO3-), H2O / 192 h / 3 - 4 °C 2: 69 percent / K2CO3 / dimethylformamide / Ambient temperature 3: 61 percent / 0.1 N aq. HCl / 3.5 h / Ambient temperature 4: HCl / ethanol View Scheme