Phosphorus trichloride → 7-Chloro-3-(2-chlorophenyl)-4-iodo-2,6-naphthyridine
Reaction equation
[Cl:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6]([I:20])=[C:7]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=3[Cl:19])[N+:8]([O-])=[CH:9]2)=[CH:4][N:3]=1.P(Cl)(Cl)Cl>ClCCl>[Cl:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6]([I:20])=[C:7]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=3[Cl:19])[N:8]=[CH:9]2)=[CH:4][N:3]=1Participants
4
Procedure
To a solution of 7-chloro-3-(2-chlorophenyl)-4-iodo-2,6-naphthyridine 2-oxide (870 mg, 2.1 mmol) in dichloromethane (13 mL) was added phosphorus trichloride (0.2 mL, 2.3 mmol). The reaction mixture was stirred at room temperature for 1 hour, and then diluted with dichloromethane (50 mL) and washed with saturated aqueous sodium bicarbonate solution (20 mL). The organic layer was separated, dried over sodium sulfate, filtered, and evaporated in vacuo to afford an orange residue that was purified by flash chromatography (silica, 40 g, ISCO, 0-30% ethyl acetate in heptane) to afford the title compound as an orange solid (400 mg, 50%). 1H NMR (400 MHz, CDCl3) δ 9.40 (s, 1H), 9.21 (s, 1H), 7.83 (s, 1H), 7.57-7.53 (m, 1H), 7.49-7.40 (m, 2H), 7.40-7.35 (m, 1H).