Potassium Fluoride → 5-[1-(ethylsulfonyl)-2,3-dihydro-1H-indol-5-yl]-1-methyl-1H-pyrrole-2-carbonitrile

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Reaction Conditions

Reaction Steps

5-Bromo-1-(ethylsulfonyl)indoline (1.85 g, 6.38 mmol), 1-methyl-5-cyano-2-pyrroleboronic acid (1.14 g, 7.7 mmol), KF (1.22 g, 21 mmol), and Pd2(dba)3 (154 mg, 0.16 mmol) were added to a round bottom flask under nitrogen. The flask was sealed and purged with nitrogen for 5 minutes. THF (16 mL) was added followed by a solution of tri-t-butylphosphine (10% wt in hexanes) (0.95 mL, 0.32 mmol) via syringe and the mixture was stirred vigorously at 25° C. for 5 hours. The mixture was diluted with ethyl acetate, filtered through a plug of silica gel, washed through with additional ethyl acetate and concentrated to give a crude brown/black semi-solid. Purification was performed using Isco chromatography (the Redisep® column, silica, gradient 10-60% ethyl acetate in hexane). Further purification via Isco chromatography (the Redisep® column, silica, gradient 50% hexane:45% methylene chloride:5% ethyl acetate) afforded 5-[1-(ethylsulfonyl)-2,3-dihydro-1H-indol-5-yl]-1-methyl-1H-pyrrole-2-carbonitrile (1.2 g) as a colorless oil. MS (EI) m/z 315.8; HPLC purity 99.4% at 210-370 nm, 9.2 min.; the Xterra® RP18 column, 3.5μ, 150×4.6 mm column, 1.2 mL/min, 85/15-5/95 (Ammonium formate buffer pH=3.5 acetonitrile+MeOH) for 10 minutes, hold 4 minutes.

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