Reaktion #58002

Reaktionsgleichung

triflate

4,5-dimethyl-2-propionylphenyl trifluoromethanesulfonate

sodium carbonate

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

→

84

tert-butyl 4-(4,5-dimethyl-2-propionylphenyl)-3,6-dihydropyridine-1(2H)-carboxylate

Lösungsmittel

ethanol toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted three times with EtOAc
2. 2
   WaschenThe combined organic extracts were washed with brine
3. 3
   Trocknendried (MgSO4)
4. 4
   Filtrationfiltered
5. 5
   Einengenthe filtrate concentrated in vacuo
6. 6
   SonstigePurification of the crude residue by flash chromatography on silica gel (gradient elution; 0%-25% EtOAc/hexanes as eluent)

Vorschrift

A vigorously stirred solution of triflate 83 (10.5 g, 33.8 mmol), aqueous sodium carbonate (50.8 mL of a 2.0 M solution, 102 mmol), tert-butyl 4(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydropyridine-1(2H)carboxylate (10.45 g, 33.8 mmol), and tetrakis(triphenylphosphine)palladium(0) (3.91 g, 3.38 mmol) in ethanol/toluene (1:1, 100 mL) was degassed via three vacuum/nitrogen ingress cycles and heated to 75° C. for 30 min. The reaction mixture was poured into ice water and extracted three times with EtOAc. The combined organic extracts were washed with brine, dried (MgSO4), filtered, and the filtrate concentrated in vacuo. Purification of the crude residue by flash chromatography on silica gel (gradient elution; 0%-25% EtOAc/hexanes as eluent) afforded 84 as a colorless oil.

Quelle