Methyl 4-aminobenzoate → Methyl 4-(pyrazin-2-ylamino)benzoate
反応式
[NH2:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:4][CH:3]=1.Cl[C:13]1[CH:18]=[N:17][CH:16]=[CH:15][N:14]=1>CCOC(C)=O>[N:14]1[CH:15]=[CH:16][N:17]=[CH:18][C:13]=1[NH:1][C:2]1[CH:3]=[CH:4][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:10][CH:11]=1参加物
4
反応条件
- 温度
- 150 °C
実験手順
Into a 250 mL roundbottom flask, was placed methyl 4-aminobenzoate (vii) (10 g, 66.23 mmol) followed by the addition of 2-chloropyrazine (75.9 g, 665.79 mmol). The resulting solution was stirred at 150° C. for 4 hours. The reaction progress was monitored by TLC (EtOAc/PE=1:2). After completion, the reaction was cooled to room temperature and the undissolved material was filtered off. The filtration was dissolved in 400 mL of water and the pH was adjustmented to 9 by the addition of Na2CO3. The resulting solution was extracted four times with 800 mL of EtOAc and the organic layers were combined and dried over Na2SO4. Removal of the solvent and volatile components from the organic layer under reduced pressure provided the crude product methyl 4-(pyrazin-2-ylamino)benzoate (viii) (13.6 g, 90% yield) as a yellow solid which was used directly in the next step without further purification.