Reaktion #313266

Reaktionsgleichung

bromine

5-Chloro-thieno[3,2-b]pyridine

sodium bicarbonate

potassium hydrogenphosphate

magnesium sulfate

Bromine

→

title compound

Ausbeute 54.2%

3-Bromo-5-chloro-thieno[3,2-b]pyridine

Ausbeute 54.2%

Lösungsmittel

CH2Cl2

water

chloroform

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturunder reflux for 30 min
2. 2
   workup.STIRRINGstirred
3. 3
   Temperaturunder reflux overnight
4. 4
   workup.STIRRINGstirred
5. 5
   Temperaturunder reflux for 1 day
6. 6
   SonstigeOrganic layer is separated
7. 7
   Extraktionextracted with CH2Cl2
8. 8
   Trocknendried over Na2SO4
9. 9
   Sonstigeevaporated

Vorschrift

1.00 g of 5-Chloro-thieno[3,2-b]pyridine (5.91 mmol), 497 mg of sodium bicarbonate (5.91 mmol), 1.54 g of potassium hydrogenphosphate (8.87 mmol) and 1.07 g of magnesium sulfate (8.87 mmol) are placed in a flask with 50 ml of chloroform. The reaction mixture is stirred under reflux for 30 min. 0.55 ml of Bromine (10.82 mmol) is added and stirred under reflux overnight. 0.55 ml of Additional bromine (10.82 mmol) is added and stirred under reflux for 1 day. The reaction mixture is cooled to room temperature and water and CH2Cl2 are added. Organic layer is separated. The water layer is adjusted to pH=14 with 5N NaOH and extracted with CH2Cl2. All organic layers are combined together and dried over Na2SO4 and evaporated. The crude product is applied onto a silica-gel chromatography column (Hexane:AcOEt=5:1) to give 796 mg of the title compound (54%). 1H-NMR (CDCl3): 8.12 (d, 1H, J=7.9 Hz), 7.81 (s, 1H), 7.36 (d, 1H, J=7.9 Hz) ppm.

Quelle