sodium azide; ammonium chloride in N,N-dimethyl-formamide T=60 - 70°C; 2 h;

1: 1.) BF3*Et2O, acetanhydride, 2.) BF3*Et2O, POCl3 / 1.) acetic acid, room temp., 2 h, 2.) room temp., 3 h, then 50 deg C, 2 h 2: 75 percent / hydroxylamine hydrochloride, HCOONa / formic acid / 2.5 h / Heating 3: 39 percent / NH4Cl, NaN3 / dimethylformamide / 2 h / 60 - 70 °C View Scheme

1: 75 percent / hydroxylamine hydrochloride, HCOONa / formic acid / 2.5 h / Heating 2: 39 percent / NH4Cl, NaN3 / dimethylformamide / 2 h / 60 - 70 °C View Scheme

1: 89 percent / F3CCOOH, trifluoroacetylimidazole / tetrahydrofuran / 2 h / Heating 2: 39 percent / NH4Cl, NaN3 / dimethylformamide / 2 h / 60 - 70 °C View Scheme