Lithium Chloride → tert-butyl 4-(quinolin-3-yl)-5,6-dihydropyridine-1(2H)-carboxylate

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Reaction Steps

3-Quinolineboronic acid (250 mg, 1.4 mmol) and tert-butyl 4-(trifluoromethylsulfonyloxy)-5,6-dihydropyridine-1(2H)-carboxylate (580 mg, 1.8 mmol) were combined and dissolved in a mixture of toluene (10 mL) and ethanol (1 mL). 2M aqueous sodium bicarbonate solution (1.5 mL, 3.0 mmol) was added to the mixture followed by lithium chloride (180 mg, 4.2 mmol). Nitrogen gas was bubbled through the mixture for 10 minutes. Tetrakis(triphenylphosphine)palladium(0) (75 mg, 0.07 mmol) was added to the mixture. Reaction was heated at reflux for 3.5 hours. Mixture was cooled to room temperature and diluted with ethyl acetate (50 mL). Mixture was washed successively with water (2×30 mL) and brine (20 mL). Organic layer was dried (magnesium sulfate), filtered and concentrated in vacuo. Silica gel chromatography afforded the desired product as lightly colored oil in 76% yield. MS m/e (M−C4H8+H)+=255.1.

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