Reaktion #69907

Reaktionsgleichung

3-Bromofuran-2-carboxylic acid methyl ester

4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid t-butyl ester

Na2CO3

→

4-(2-methoxycarbonylfuran-3-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid t-butyl ester

Ausbeute 69.7%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe mixture was degassed
2. 2
   Sonstigepurged with nitrogen (3×)
3. 3
   Sonstigethe mixture was again degassed
4. 4
   Sonstigepurged with nitrogen (3×)
5. 5
   TemperaturThe mixture was then cooled
6. 6
   Sonstigethe layers were separated
7. 7
   workup.ADDITIONThe THF layer was diluted with EtOAc (100 mL)
8. 8
   Waschenwashed with saturated aqueous NaCl (50 mL)
9. 9
   Trocknendried over Na2SO4
10. 10
    FiltrationThe material was filtered
11. 11
    Sonstigepurified by chromatography with PE/EtOAc (50:1 to 10:1)

Vorschrift

3-Bromofuran-2-carboxylic acid methyl ester (2.0 g, 9.8 mmol, 1.0 eq.), 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid t-butyl ester (3.1 g, 10 mmol, 1.0 eq.), THF (100 mL) and Na2CO3 (20 mL, 40 mmol, 4.0 eq.) were combined. The mixture was degassed and purged with nitrogen (3×). PdCl2(PPh3)2 (0.2 g, 0.3 mmol, 0.03 eq.) was added, and the mixture was again degassed and purged with nitrogen (3×), then heated at 80° C. overnight. The mixture was then cooled and the layers were separated. The THF layer was diluted with EtOAc (100 mL), washed with saturated aqueous NaCl (50 mL) and dried over Na2SO4. The material was filtered and applied onto a silica gel column and purified by chromatography with PE/EtOAc (50:1 to 10:1) to yield 4-(2-methoxycarbonylfuran-3-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid t-butyl ester (2.1 g) as a white solid.

Quelle