[NH2:1][C:2]1[CH:10]=[CH:9][C:5]2[N:6]=[CH:7][NH:8][C:4]=2[CH:3]=1.[H-].[Na+].[CH3:13][S:14][C:15]1[N:20]=[C:19](Cl)[CH:18]=[CH:17][N:16]=1>CN(C=O)C>[CH3:13][S:14][C:15]1[N:20]=[C:19]([N:8]2[C:4]3[CH:3]=[C:2]([NH2:1])[CH:10]=[CH:9][C:5]=3[N:6]=[CH:7]2)[CH:18]=[CH:17][N:16]=1.[CH3:13][S:14][C:15]1[N:20]=[C:19]([N:6]2[C:5]3[CH:9]=[CH:10][C:2]([NH2:1])=[CH:3][C:4]=3[N:8]=[CH:7]2)[CH:18]=[CH:17][N:16]=1To a stirred solution of 5-aminobenzimidazole (700 mg, 5.26 mmol, 1 eq) in DMF (21 mL) was added NaH (231 mg, 5.78 mmol, 1.1 eq, (60% suspension in oil)). The mixture was allowed to stir until gas evolution ceased. To the DMF solution was added 2-methylthio-4-chloropyrimidine (0.612 mL, 5.26 mmol, 1 eq) dropwise via syringe. The mixture was allowed to stir overnight. The DMF was removed under reduced pressure and the residue was diluted with water and extracted 3× with CH2Cl2. The organic extracts were combined, dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure. The mixture was purified by preparative thin layer chromatography (eluted 2× with 3.5% MeOH/CH2Cl2) to give 149 mg 2-methylthio-4-[6-aminobenzimidazol-1-yl]pyrimidine (faster regioisomer) and 89 mg 2-methylthio-4-[5-aminobenzimidazol-1-yl]pyrimidine (slower regioisomer).
Wird geladen…
