Sodium Carbonate → Methyl 6-bromo-2-methylpyrimidine-4-carboxylate

Reaktionsgleichung

P(Br)(Br)([Br:3])=O.O[C:7]1[N:12]=[C:11]([CH3:13])[N:10]=[C:9]([C:14]([O:16][CH3:17])=[O:15])[CH:8]=1.C(=O)([O-])[O-].[Na+].[Na+]>CN(C=O)C>[Br:3][C:7]1[N:12]=[C:11]([CH3:13])[N:10]=[C:9]([C:14]([O:16][CH3:17])=[O:15])[CH:8]=1

Komponenten

Versuchsvorschrift

POBr3 (6.65 g, 23.2 mmol, Spectrochem) was added to a stirred solution of methyl 6-hydroxy-2-methylpyrimidine-4-carboxylate (5.0 g, 29.7 mmol, Preparation #2) in DMF (100 mL) at about 90° C. The reaction mixture was heated at the same temperature for about another 10 min and poured into ice water (500 mL). The solution was neutralized with 10% aqueous sodium carbonate solution (pH 7). This solution was extracted with EtOAc (3×200 mL). The combined organic layer was washed with water (2×100 mL) and brine solution (2×150 mL), and dried over sodium sulphate and concentrated in vacuum. The crude material was purified by silica gel chromatography using 15 to 25% of EtOAc in hexane as the eluent. Relevant fractions containing the required compound were combined and evaporated to dryness under reduced pressure to afford methyl 6-bromo-2-methylpyrimidine-4-carboxylate as an off white solid 5.2 g (75.7%). 1H NMR (400 MHz, DMSO) δ: 8.02 (s, 1H), 4.03 (s, 3H), 2.83 (s, 3H); MS m/z: 231 (M+H)+.