N-bromobutanimide → Ethyl 5-bromo-2-methylthiazole-4-carboxylate

反応式

[CH3:1][C:2]1[S:3][CH:4]=[C:5]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[N:6]=1.C1C(=O)N([Br:19])C(=O)C1.C([O-])(O)=O.[Na+]>CC#N>[Br:19][C:4]1[S:3][C:2]([CH3:1])=[N:6][C:5]=1[C:7]([O:9][CH2:10][CH3:11])=[O:8]

参加物

実験手順

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.