Bromine → HCID 58432991, Verbindung

Reaktionsgleichung

[C:1]([O:5][C:6]([C:8]1[C:9]([C:13]2[CH:18]=[CH:17][C:16]([Cl:19])=[CH:15][CH:14]=2)=[N:10][S:11][CH:12]=1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[Li]CCCC.[Br:25]Br>C1COCC1>[C:1]([O:5][C:6]([C:8]1[C:9]([C:13]2[CH:14]=[CH:15][C:16]([Cl:19])=[CH:17][CH:18]=2)=[N:10][S:11][C:12]=1[Br:25])=[O:7])([CH3:4])([CH3:2])[CH3:3]

Komponenten

Versuchsvorschrift

A solution of 8 (3.50 g) in THF (60 ml) is cooled to −78° C. under N2 followed by drop wise addition of BuLi (8.0 ml, 1.6M in hexane). After complete addition stirring is continued at −78° C. for 15 min. Bromine (1.2 ml) is now added drop wise and stirring is continued at −78° C. for 15 min, after which the cooling bath is removed. The mixture is allowed to warm to room temp. TLC shows a good conversion into a slightly faster moving spot (Hep/EA, 9/1). 1N HCl (50 ml) is added and the THF is removed in vacuo. Water (100 ml), containing some sodium thiosulfate, is added and the product is extracted with EtOAc (150 ml). The organic layer is washed with sat. NaHCO3, brine, dried and concentrated. The orange/red oily residue is purified by flash column chromatography (˜50 g silica, 5% diisopropyl ether in heptane) yielding 3.1 g of 9 as a pale yellow oil.