sodium azide; N-ethyl-N-methylpyrrolidinium tetrafluoroborate; tetrabutylammomium bromide in water T=55°C; 0.5 h;

1: 82 percent / NaN3 / toluene / 1.) rt, 1 h, 2.) reflux, 1 h 2: 75 percent / toluene / 0.5 h / Ambient temperature 3: 80 percent / trifluoroacetic acid / Ambient temperature View Scheme

1: 75 percent / toluene / 0.5 h / Ambient temperature 2: 80 percent / trifluoroacetic acid / Ambient temperature View Scheme