Reaktion #84789

Reaktionsgleichung

4-bromo-1-(tris(4-methoxyphenyl)methyl)-1H-pyrazole

(4-formylphenyl)boronic acid

K2CO3

→

4-(1-(tris(4-methoxyphenyl)methyl)-1H-pyrazol-4-yl)benzaldehyde

Ausbeute 83.7%

Lösungsmittel

DME H2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas degassed
2. 2
   workup.WAITby alternately putting under house vacuum and argon three times for several minutes
3. 3
   Sonstigethe mixture was degassed again
4. 4
   Temperaturcooling to room temperature
5. 5
   workup.ADDITIONH2O was added
6. 6
   ExtraktionThe mixture was extracted with EtOAc
7. 7
   Waschenthe combined organics were washed with H2O, saturated aqueous NaHCO3 and brine
8. 8
   Trocknenthen dried over Na2SO4
9. 9
   Einengenconcentrated in vacuo
10. 10
    SonstigePurification by chromatography (20-30% EtOAc-hexanes; EtOAc containing 1% Et3N)

Vorschrift

A mixture of 4-bromo-1-(tris(4-methoxyphenyl)methyl)-1H-pyrazole (1.47 g, 3.1 mmol), (4-formylphenyl)boronic acid (0.94 g, 6.3 mmol), and K2CO3 (0.65 g, 4.7 mmol) in DME-H2O (25 mL, 4:1) was degassed by alternately putting under house vacuum and argon three times for several minutes each. Tetrakis(triphenylphosphine)palladium (0.35 g, 0.3 mmol) was added then the mixture was degassed again. After heating for 16.5 hrs at 80° C. and cooling to room temperature, H2O was added. The mixture was extracted with EtOAc and the combined organics were washed with H2O, saturated aqueous NaHCO3 and brine then dried over Na2SO4 and concentrated in vacuo. Purification by chromatography (20-30% EtOAc-hexanes; EtOAc containing 1% Et3N) gave 4-(1-(tris(4-methoxyphenyl)methyl)-1H-pyrazol-4-yl)benzaldehyde (1.31 g combined from two reactions, 33%).

Quelle