Cesium carbonate → 4-Chloro-3-cyclopropylpyridine

Temperatur

115 °C

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+).

1. temperaturecooled down to room temperature
2. filtrationfiltered through a pad of celite
3. additionThe filtrate was poured into a separatory funnel
4. additiondiluted with ethyl acetate
5. extractionextracted with an aqueous solution 1.0M sodium bicarbonate
6. customThe organic phase was collected
7. dry with materialdried over sodium sulfate
8. customevaporated down to dryness
9. customThe crude material was purified by flash chromatography on silica eluting with a heptane/(solution 3% triethylamine in ethyl acetate) gradient

ORD-Eintrag

ord-b1c548f67a4c4d1baa93d74c5462dd23

Quelldatensatz

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09409866B2