Reaktion #471126

Reaktionsgleichung

NaHCO3

NBS

ethyl 2-methyl-1,3-thiazole-4-carboxylate

NBS

→

ethyl 5-bromo-2-methyl-1,3-thiazole-4-carboxylate

Ausbeute 40.1%

Lösungsmittel

MeCN

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturby heating
2. 2
   Temperaturunder reflux for 3 hours
3. 3
   Temperaturby heating
4. 4
   Temperaturunder reflux for 2 hours
5. 5
   TemperaturUnder ice-cooling, to the reaction mixture
6. 6
   Extraktionextraction with EtOAc
7. 7
   TrocknenThe organic layer was dried over MgSO4
8. 8
   Einengenconcentrated under reduced pressure
9. 9
   SonstigeThe residue obtained
10. 10
    Sonstigewas purified by silica gel column chromatography (hexane:EtOAc=from 100:0 to 60:40)

Vorschrift

To a solution of ethyl 2-methyl-1,3-thiazole-4-carboxylate (14.53 g) in MeCN (150 mL) was added NBS (22.66 g), followed by heating under reflux for 3 hours. To the reaction mixture was added NBS (7.55 g), followed by heating under reflux for 2 hours. Under ice-cooling, to the reaction mixture was added a saturated aqueous NaHCO3 solution, followed by stirring for 5 minutes, and then extraction with EtOAc. The organic layer was dried over MgSO4 and then concentrated under reduced pressure. The residue obtained was purified by silica gel column chromatography (hexane:EtOAc=from 100:0 to 60:40) to obtain ethyl 5-bromo-2-methyl-1,3-thiazole-4-carboxylate (8.52 g) as a yellow solid.

Quelle