N-bromobutanimide → ethyl 3-((2-bromo-6-chloro-7-fluoro-1-(1-propyl-1H-pyrazol-4-yl)-1H-indol-3-yl)thio)-2-fluorobenzoate

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Reaction Steps

To a stirred solution of compound 2 (200 mg, 0.42 mmol) in CCl4 (3 mL) under inert atmosphere was added NBS (150 mg, 0.84 mmol) at RT and stirred for 16 h. The reaction was monitored by TLC and LC-MS; after completion of the reaction, the reaction mixture was diluted with water (20 mL) and extracted with CH2Cl2 (2×20 mL). The combined organic extracts were washed with brine (15 mL), dried over Na2SO4, filtered and concentrated under reduced pressure to obtain the crude. This was purified by silica gel column chromatography using 10-15% EtOAc/Hexanes to afford compound 3 (100 mg, 43%) as an off-white solid. 1H NMR (400 MHz, CDCl3): δ 7.71-7.67 (m, 1H), 7.66 (s, 1H), 7.64 (s, 1H), 7.31 (d, J=8.8 Hz, 1H), 7.18-7.15 (m, 1H), 7.00-6.96 (m, 2H), 4.40 (q, J=7.2 Hz, 2H), 4.18 (t, J=7.2 Hz, 2H), 2.02-1.93 (m, 2H), 1.40 (t, J=7.2 Hz, 3H), 0.97 (t, J=7.2 Hz, 3H); LC-MS (ESI): 98.1%; m/z 556.2 (M+2); (column: X Select CSH C-18, 50×3.0 mm, 3.5 μm); RT 4.94 min; 5 mM NH4OAc: ACN; 0.8 mL/min).

Provenance & Evidence