N,N'-Dimethylethylenediamine → 6-chloro-7-fluoro-1-(pyridin-3-yl)-1H-indole

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of indole 1 (Example 4, Step 1; 2.0 g, 11.8 mmol) in toluene (50 mL) were added 3-bromopyridine (2.9 g, 17.7 mmol), N,N′-dimethylethylenediamine (418 mg, 4.73 mmol), K3PO4 (6.3 g, 29.5 mmol), CuI (225 mg, 1.18 mmol) at RT under inert atmosphere. The mixture was purged with argon for 15 min and heated to 140° C. in a sealed tube for 16 h. The reaction mixture was cooled to RT, added n-hexane (20 mL), stirred for 5 minutes and then filtered. The filtrate was diluted with water (20 mL) and extracted with EtOAc (2×50 mL). The combined organic extracts were washed with water and brine solution, dried over Na2SO4, filtered and concentrated under reduced pressure to obtain the crude. The crude was purified (silica gel; 10% EtOAc/Hexanes) to afford compound 2 (2.0 g, 69%) as light brown solid. 1H NMR (500 MHz, DMSO-d6): δ 8.84 (s, 1H), 8.66 (d, J=5.0 Hz, 1H), 8.06-8.02 (m, 1H), 7.74-7.72 (m, 1H), 7.64-7.58 (m, 1H), 7.52 (d, J=8.0 Hz, 1H), 7.28-7.24 (m, 1H), 6.82 (m, 1H).

Provenance & Evidence