Reaktion #45138

Reaktionsgleichung

sodium hydrogen carbonate

methyl 5-chloropyrazine-2-carboxylate

tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylate

triphenylphosphine

→

5-[1-[(2-methylpropan-2-yl)oxycarbonyl]-3,6-dihydro-2H -pyridin-4-yl]pyrazine-2-carboxylic acid

Ausbeute 100.0%

Lösungsmittel

water

1,2-dimethoxyethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenwashed with EtOAc (50 mL)
2. 2
   Extraktionextracted with EtOAc (2×50 mL)
3. 3
   TrocknenThe combined organics were dried over MgSO4
4. 4
   Einengenconcentrated under reduced pressure

Vorschrift

Saturated aqueous sodium hydrogen carbonate solution (5.00 ml) was added to methyl 5-chloropyrazine-2-carboxylate (173 mg, 1.00 mmol), tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylate (371 mg, 1.20 mmol), palladium(II) acetate (11 mg, 0.05 mmol) and triphenylphosphine (52 mg, 0.20 mmol) in 1,2-dimethoxyethane (5.00 ml) at 25° C. under nitrogen. The resulting mixture was stirred at 80° C. for 4 h. The reaction mixture was diluted with water (50 mL) and washed with EtOAc (50 mL). The aqueous layer was adjusted to pH 1 using HCl (2M aqueous solution) and extracted with EtOAc (2×50 mL). The combined organics were dried over MgSO4 and concentrated under reduced pressure to afford 5-[1-[(2-methylpropan-2-yl)oxycarbonyl]-3,6-dihydro-2H -pyridin-4-yl]pyrazine-2-carboxylic acid (305 mg, 100%) as a yellow solid. This was used directly in the next reaction, with no further purification.

Quelle