Reaktion #46481

Reaktionsgleichung

chlorotrimethylsilane

N-bromosuccinamide

4′-Piperidinoacetophenone

lithium bis(trimethylsilyl)amide

→

2-bromo-4′-piperidinoacetophenone

Lösungsmittel

ethyl acetate

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   Temperaturthe mixture was refluxed from 4 hours
3. 3
   Sonstigewas further purified by silica gel chromatography
4. 4
   Wascheneluting with 3:1 hexane/ethyl acetate

Vorschrift

4′-Piperidinoacetophenone (203 mg, 1.00 mmol) was dissolved in THF (5 mL) and treated with lithium bis(trimethylsilyl)amide (1.10 mL, 11.0M in THF, 1.10 mmol). The solution was stirred for 30 minutes prior to the addition of chlorotrimethylsilane (140 μL, 1.10 mmol). After stirring for an additional 30 minutes N-bromosuccinamide (300 mg, 1.73 mmol) was added and the mixture was refluxed from 4 hours. Standard aqueous/ethyl acetate workup provided a yellow solid which was further purified by silica gel chromatography, eluting with 3:1 hexane/ethyl acetate, to provide 2-bromo-4′-piperidinoacetophenone as an off white solid (209 mg, 74%). 1H NMR (200 MHz, CDCl3) δ 8.75 (d, 2H), 6.84 (d, 2H), 4.61 (s, 2H), 3.40 (m, 4H), 1.68 (m, 6H).

Quelle