Cornforth reagent → 1-(5-Bromo-2-chlorophenyl)ethan-1-one
Reaktionsgleichung
[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[Br:22][C:23]1[CH:24]=[CH:25][C:26]([Cl:32])=[C:27]([CH:29]([OH:31])[CH3:30])[CH:28]=1>C(Cl)Cl>[Br:22][C:23]1[CH:24]=[CH:25][C:26]([Cl:32])=[C:27]([C:29](=[O:31])[CH3:30])[CH:28]=1Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
Pyridinium dichromate (2.6 g, 6.94 mmol) was added to a solution of 1-(5-bromo-2-chloro-phenyl)-ethanol (1.09 g, 4.6 mmol) in CH2Cl2 (20 mL). The reaction was stirred for 15 hours and then more pyridinium dichromate (2.6 g, 6.94 mmol) was added. After another 24 hours celite was added and the mixture was stirred for 20 mins. The reaction mixture was filtered through a pad of celite washing with ether. The filtrate was concentrated to a brown oil. The residue was purified by flash silica gel chromatography (0% to 10% EtOAc in hexanes) to give the title compound as a clear oil (0.92 g, 85%). 1H NMR (400 MHz, CDCl3): δ 2.64 (s, 3H), 7.29 (d, J=8.6 Hz, 1H), 7.51 (dd, J=8.6, 2.3 Hz, 1H), 7.66 (d, J=2.3 Hz, 1H).