in N,N-dimethyl-formamide T=20°C; 1 h;

1: 1.) (Pho)2P(O)N3 / 1) benzene, 20 deg C (0.5 h), 80 deg C (1 h); 2) 80 deg C, 30 h 2: 48 percent / aq. NaOH / methanol / 1) 20 deg C, 3 h; 2) reflux, 14 h View Scheme