Carbon tetrabromide → 3-(3-Bromopropyl)-5-nitro-1H-indole

Participants

Reaction Steps

To a solution of triphenylphosphine (6.70 g, 0.025 mol) in 80 mL of acetonitrile was added a solution of 5-nitro-3-(3-hydroxypropyl)indole (18) (4.30 g, 0.020 mol) in 75 mL of acetonitrile, followed by a solution of CBr4 (9.00 g, 0.027 mol) in 25 mL of acetonitrile, at 0° C. under Ar. The mixture was stirred at room temperature for 3 h and then it was evaporated and the residue was chromatographed (SiO2 /ethyl acetate-hexane, 1:9 then 1:4) to give the title compound (4.60 g, 84%) as a solid, mp 92°-95° C.: IR (neat) 3420, 1330 cm-1 ; 1H NMR (CDCl3, 200 MHz) δ 8.59 (d, J=2.1 Hz, 1H), 8.40 (br s, 1H), 8.13 (dd, J=9.0, 2.2 Hz, 1H), 7.40 (d, J=9.1 Hz, 1H), 7.21 (d, J=2.2 Hz, 1H), 3.45 (t, J=6.4 Hz, 2H), 2.99 (t, J=7.2 Hz, 2H), 2.26 (m, 2H).

Provenance & Evidence