[NH2:1][C:2]1[C:7]([NH2:8])=[CH:6][C:5]([Br:9])=[CH:4][N:3]=1.[CH2:10]([O:12][C:13]1[CH:14]=[C:15]([CH:19]=[CH:20][CH:21]=1)[C:16](O)=O)[CH3:11].P(Cl)(Cl)(Cl)=O.[OH-].[Na+]>>[Br:9][C:5]1[CH:6]=[C:7]2[NH:8][C:16]([C:15]3[CH:19]=[CH:20][CH:21]=[C:13]([O:12][CH2:10][CH3:11])[CH:14]=3)=[N:1][C:2]2=[N:3][CH:4]=1A mixture of 2,3-diamino-5-bromopyridine (Compound of Reference Example 1) (1.13 g), 3-ethoxybenzoic acid (997 mg) and phosphorus oxychloride (24 ml) was stirred at 120° C. for 2 hours and poured onto ice. The mixture was neutralized with 8 N sodium hydroxide, stirred for 20 minutes and extracted with ethyl acetate-tetrahydrofuran (3:1, v/v). The organic layer was washed with water, dried over MgSO4. The solvent was distilled off under reduced pressure and the resulting crystals were collected by filtration to obtain 6-bromo-2-(3-ethoxyphenyl)-1H-imidazo[4,5-b]pyridine (978 mg, 51%).
Wird geladen…
