[Br:1][C:2]1[N:3]=[C:4](Br)[C:5]2[N:6]([CH:8]=[CH:9][N:10]=2)[CH:7]=1.[C:12]([O:16][C:17]([N:19]1[CH2:24][CH2:23][N:22]([C:25]2[CH:30]=[CH:29][C:28]([NH2:31])=[CH:27][CH:26]=2)[CH2:21][CH2:20]1)=[O:18])([CH3:15])([CH3:14])[CH3:13].C(=O)([O-])[O-].[K+].[K+].C(#N)C>O.CN(C)C(=O)C>[C:12]([O:16][C:17]([N:19]1[CH2:24][CH2:23][N:22]([C:25]2[CH:26]=[CH:27][C:28]([NH:31][C:4]3[C:5]4[N:6]([CH:8]=[CH:9][N:10]=4)[CH:7]=[C:2]([Br:1])[N:3]=3)=[CH:29][CH:30]=2)[CH2:21][CH2:20]1)=[O:18])([CH3:15])([CH3:13])[CH3:14]A mixture of 6,8-dibromoimidazo[1,2-a]pyrazine (12.5 mmol), 4-(4-amino-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (12) (13.1 mmol), potassium carbonate (25 mmol), acetonitrile (50 mL) and N,N-dimethylacetamide (20 mL) is heated at 65° C. for 16 hrs. The mixture is cooled to room temperature, treated water (100 mL), and extracted with ethyl acetate (3×80 mL). The extracts are washed with water (3×60 mL) and brine (1×60 mL), dried over magnesium sulfate, and concentrated in vacuo. The residue is chromatographed over silica gel, eluting with ethyl acetate, to give 4-[4-(6-bromo-imidazo[1,2-a]pyrazin-8-ylamino)-phenyl]-piperazine-1-carboxylic acid tert-butyl ester (13) as a light brown foam.
Wird geladen…