Cesium carbonate → 4-Chloro-3-cyclopropylpyridine

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-bromo-4-chloropyridine (CAN 36953-42-1, 4 g, 20.8 mmol) in a mixture of toluene (72 ml) and water (8.5 ml) under an argon atmosphere were added potassium cyclopropyltrifluoroborate (3.23 g, 21.8 mmol), palladium (II) acetate (93.3 mg, 416 μmol), butyldi-1-adamantylphosphine (224 mg, 624 μmol) and cesium carbonate (16.9 g, 52.0 mmol). The reaction mixture was stirred overnight at 115° C., cooled down to room temperature and filtered through a pad of celite. The filtrate was poured into a separatory funnel, diluted with ethyl acetate and extracted with an aqueous solution 1.0M sodium bicarbonate. The organic phase was collected, dried over sodium sulfate and evaporated down to dryness. The crude material was purified by flash chromatography on silica eluting with a heptane/(solution 3% triethylamine in ethyl acetate) gradient to yield the title product (2.39 g, 75%) as a yellow liquid. MS (ESI, m/z): 154.0 (M+H+).

Provenance & Evidence