in toluene 1) 15 min., 65-72 deg C; 2) 1.5 h, 70-80 deg C;

1: 1) NaN3 / 1) water, acetone, 10-15 deg C, 2 h; 2) benzene, 30 min, 60-68 deg C, then 2h, 70 deg C 2: 94 percent / toluene / 1) 15 min., 65-72 deg C; 2) 1.5 h, 70-80 deg C View Scheme