in N,N-dimethyl acetamide T=140 - 142°C; 7 h;

1: 82 percent / 90percent nitric acid, 98percent sulfuric acid / 1.) 0 deg C, 15 min, 2.) RT, 4 h 2: 53 percent / conc. hydrochloric acid, stannous chloride dihydrate / acetic acid / 1.) 0 deg C, 30 min, 2.) RT, 3 h 3: 1.) 2N hydrochloric acid, sodium nitrite, 2.) cuprous chloride, conc. hydrochloric acid / 1.) 0 deg c to 5 deg C, 15 min, 2.) benzene, a) 0 deg C, 15 min, b) RT, 2 h View Scheme