N,N'-Dimethylethylenediamine → 6-chloro-1-(1-propyl-1H-pyrazol-4-yl)-1H-indole

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 6-chloro-1H-indole 1 (1.0 g, 6.62 mmol) in toluene (25 mL) under inert atmosphere were added N,N′-dimethylethylene diamine (233 mg, 2.64 mmol), potassium phosphate (3.50 g, 16.55 mmol) and 4-bromo-1-propyl-1H-pyrazole (Intermediate B; 1.23 g, 6.62 mmol) at RT and then degassed under argon for 15 min. To this, CuI (126 mg, 0.66 mmol) was added and sealed the tube. The reaction mixture was heated to 140° C. and stirred for 12 h. The reaction was monitored by TLC; after completion of the reaction, the reaction mixture was filtered and the filtrate was concentrated under reduced pressure to obtain the crude. This was purified by silica gel column chromatography using 10-15% EtOAc/Hexanes to afford compound 2 (1.5 g, 88%) as yellow oil. 1H NMR (500 MHz, CDCl3): δ 7.68 (s, 1H), 7.62 (s, 1H), 7.55 (d, J=10.0 Hz, 1H), 7.35 (s, 1H), 7.17 (d, J=3.5 Hz, 1H), 7.11 (d, J=10.0 Hz, 1H), 6.59 (d, J=3.5 Hz, 1H), 4.17 (t, J=7.5 Hz, 2H), 2.00-1.96 (m, 2H), 1.00 (t, J=7.5 Hz, 3H); LC-MS (ESI): 93.3%; m/z 260.2 (M+H+); (column: X Select CSH C-18, 50×3.0 mm, 3.5 μm); RT 4.04 min; 5 mM NH4OAc: ACN; 0.8 mL/min).

Provenance & Evidence