[Cl:1]N1C(=O)CCC1=O.CN(C)C=O.[Br:14][C:15]1[CH:16]=[CH:17][C:18]([NH2:21])=[N:19][CH:20]=1.[OH-].[Na+]>O>[Br:14][C:15]1[CH:16]=[C:17]([Cl:1])[C:18]([NH2:21])=[N:19][CH:20]=1With cooling with ice, 1-chloropyrrolidine-2,5-dione (10 g, 76 mmol) was added to an N,N-dimethylformamide solution (30 ml) of 5-bromopyridine-2-amine (12 g, 69 mmol), and stirred for 4 hours. The reaction solution was diluted with water, neutralized with aqueous 5 N sodium hydroxide solution, and extracted with diethyl ether. The organic layer was washed with saturated saline water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane:chloroform:ethyl acetate=25:25:50) to obtain 5-bromo-3-chloropyridine-2-amine (12.6 g, yield: 88%) as a brown solid.
Wird geladen…
