Reaktion #55981

Reaktionsgleichung

2,6-dibromopyridine

Thiophenol

→

2-bromo-6-phenylthiopyridine

Lösungsmittel

tetrahydrofuran

hexamethylphosphorictriamide

tetrahydrofuran

water

hexamethylphosphorictriamide

hexamethylphosphorictriamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   WaschenTo sodium hydride, 0.91 g, (22.3 mmol) (washed with hexane)
2. 2
   workup.ADDITIONis added, under nitrogen
3. 3
   TemperaturThe suspension is then cooled in an ice bath
4. 4
   Temperaturthe solution is refluxed for 3 days
5. 5
   Extraktionextracted with ether
6. 6
   Waschenwashed with 5% sodium hydroxide (2×), water (3×) and brine
7. 7
   Trocknendried over magnesium sulfate
8. 8
   Einengenconcentrated
9. 9
   WaschenThe residue is finally washed with 100 ml cold (ice bath) hexane

Vorschrift

To sodium hydride, 0.91 g, (22.3 mmol) (washed with hexane) is added, under nitrogen, 8 ml of tetrahydrofuran. The suspension is then cooled in an ice bath. Thiophenol (2.32 g, 21.1 mmol) in 8 ml of tetrahydrofuran is added dropwise over 30 minutes, after which 4 ml of hexamethylphosphorictriamide is added. The solution is added dropwise over 15 hr to 5 g (21.1 mmol) 2,6-dibromopyridine in 8 ml tetrahydrofuran and 2 ml hexamethylphosphorictriamide at 24°. The reaction mixture is stirred overnight under nitrogen. After addition of 2 ml hexamethylphosphorictriamide, the solution is refluxed for 3 days, then diluted with water and extracted with ether, washed with 5% sodium hydroxide (2×), water (3×) and brine, dried over magnesium sulfate and concentrated. The residue is finally washed with 100 ml cold (ice bath) hexane to give 2-bromo-6-phenylthiopyridine, m.p. 47°.

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