Formic Acid → 2-(7-bromo-1H-benzimidazol-1-yl)ethanol
Reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([Br:8])[C:3]=1[NH:9][CH2:10][CH2:11][OH:12].Cl.[CH:14](O)=O>>[Br:8][C:4]1[C:3]2[N:9]([CH2:10][CH2:11][OH:12])[CH:14]=[N:1][C:2]=2[CH:7]=[CH:6][CH:5]=1Participants
4
Procedure
2-[(2-Amino-6-bromophenyl)amino]ethanol (0.14 g, 0.54 mmol) was dissolved in formic acid (3 mL) and irradiated in microwave oven at 135° C. for 2 h. The mixture was cooled and treated with 37% hydrochloric acid (1 mL) at 50° C. for 0.5 h. The volatiles were removed under reduced pressure. The residue was partitioned between ethyl acetate and to saturated aqueous sodium bicarbonate. The organic phase was washed with water and brine, dried over sodium sulfate and concentrated to yield 2-(7-bromo-1H-benzimidazol-1-yl)ethanol, 0.14 g (90%). MS (ESI) m/z: 241.09 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ 3.76 (q, J=5.5 Hz, 2H) 4.55 (t, J=5.4 Hz, 2H) 4.97 (t, J=5.4 Hz, 1H) 7.12 (m, 1H) 7.43 (m, 1H) 7.66 (dd, J=8.0, 1.0 Hz, 1H) 8.19 (s, 1H).