ammonium formate; sodium cyanoborohydride in ethanol T=20°C; 24 h;

1.1: NaH / dimethylformamide / 1 h / 20 °C 1.2: 88 percent / dimethylformamide / 12 h / 20 °C 2.1: 83 percent / aq. HCl / tetrahydrofuran / 16 h / 20 °C 3.1: ammonium formate; NaBH3CN / ethanol / 24 h / 20 °C View Scheme

1: 83 percent / aq. HCl / tetrahydrofuran / 16 h / 20 °C 2: ammonium formate; NaBH3CN / ethanol / 24 h / 20 °C View Scheme