N,N'-Dimethylethylenediamine → 6-chloro-2-cyclopropyl-1-(1-ethyl-1H-pyrazol-4-yl)-7-fluoro-1H-indole

Participants

Reaction Conditions

Reaction Steps

To a solution of compound 3 (4.3 g, 20.5 mmol) in toluene (50 mL) were added 4-bromo-1-ethyl-1H-pyrazole 4 (Example 2, Step 3; 4.0 g, 22.8 mmol), potassium phosphate (11.0 g, 51.2 mmol), N,N′-dimethylethylenediamine (722 mg, 8.2 mmol) and Cu(I)I (390 mg, 2.0 mmol) at RT under inert atmosphere. The reaction solution was purged with argon for 15 min and then sealed the tube. The reaction mixture was heated to 140° C. and stirred for 16 h. After completion of the reaction (TLC), the reaction mixture was cooled to RT, diluted with EtOAc (50 mL) and filtered. The filtrate was washed with water (40 mL), brine (40 mL), dried over Na2SO4, filtered and concentrated under reduced pressure to obtain the crude. The crude was purified (silica gel column chromatography; 9% EtOAc/Hexanes) to afford compound 5 (3.9 g, 63%) as a pale brown solid. 1H NMR (400 MHz, CDCl3): δ 7.64 (s, 1H), 7.60 (s, 1H), 7.16 (d, J=8.4 Hz, 1H), 7.01 (dd, J=8.4, 6.4 Hz, 1H), 6.12 (s, 1H), 4.25 (q, J=7.2 Hz, 2H), 1.69-1.62 (m, 1H), 1.56 (t, J=7.2 Hz, 3H), 0.92-0.87 (m, 2H), 0.76-0.72 (m, 2H); LC-MS (ESI): 98.6%; m/z 304.3 (M+H+); (column: X Select C-18, 50×3.0 mm, 3.5 μm); RT 4.23 min; 5 mM NH4OAc: ACN; 0.8 mL/min).

Provenance & Evidence