1: 62 percent / bromine / acetic acid / 4 h / Ambient temperature 2: 1) BuLi, 2) nitrobenzene / 1) THF, hexane, -60 deg C, 45 min, 2) THF, hexane, -196 to -60 deg C and 3.5 h at -60 deg C 3: 1) ClCOOEt, 2) 48percent aq. HBr / 1) toluene, reflux, 2 h, 2) 5 h, reflux View Scheme

hydrogen bromide; chloroformic acid ethyl ester 1) toluene, reflux, 2 h, 2) 5 h, reflux; Yield given. Multistep reaction;

1: 1) BuLi, 2) nitrobenzene / 1) THF, hexane, -60 deg C, 45 min, 2) THF, hexane, -196 to -60 deg C and 3.5 h at -60 deg C 2: 1) ClCOOEt, 2) 48percent aq. HBr / 1) toluene, reflux, 2 h, 2) 5 h, reflux View Scheme