Reaktion #70267

Reaktionsgleichung

DCM

Cs2CO3

2-chloro-5-nitro-3-phenylpyridine

Intermediate 3

2-chloro-5-nitro-3-phenylpyridine

2-cyclopropyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

→

2-cyclopropyl-5-nitro-3-phenylpyridine

Ausbeute 17.5%

Lösungsmittel

dioxane water

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solvent was evaporated
2. 2
   Extraktionthe crude mixture was extracted between water and ethyl acetate
3. 3
   SonstigeThe solid residue was purified by chromatography over SiO2 eluting with hexane/ethyl acetate

Vorschrift

In a schlenck tube, a mixture of 2-chloro-5-nitro-3-phenylpyridine (described in Intermediate 3 (step B)) (1.43 mmol, 0.4 g), 2-cyclopropyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.59 mmol, 0.29 ml), PdCl2dppf.DCM (0.14 mmol, 0.12 g), Cs2CO3 (4.3 mmol, 1.4 g) in a dioxane/water 4:1 mixture (6.5 ml) was heated at 100° C. for 16 hours, under argon atmosphere. The solvent was evaporated and the crude mixture was extracted between water and ethyl acetate. The solid residue was purified by chromatography over SiO2 eluting with hexane/ethyl acetate mixtures affording 2-cyclopropyl-5-nitro-3-phenylpyridine (0.06 g, 17% of yield) of the expected product.

Quelle