[C:1]([NH2:5])([CH3:4])([CH3:3])[CH3:2].[C:6]([NH:13][CH2:14][CH2:15][C:16](O)=[O:17])([O:8][C:9]([CH3:12])([CH3:11])[CH3:10])=[O:7].C(N(CC)CC)C.[I-].ClC1C=CC=C[N+]=1C>C(Cl)Cl.C1CCCCC1.CCOC(C)=O>[C:9]([O:8][C:6]([NH:13][CH2:14][CH2:15][C:16]([NH:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:17])=[O:7])([CH3:12])([CH3:11])[CH3:10]To a mixture of tert-butylamine (210 μl; 2 mmol; 1 eq) and boc-beta-alanine (416.3 mg; 2.20 mmol; 1.10 eq) in DCM (30 ml), are added triethylamine (832 μl; 6 mmol; 3 eq) and 2-chloro-1-methylpyridinium iodide (1 533 mg; 6 mmol; 3 eq). The mixture is stirred overnight at RT. The reaction is followed by TLC (cyclohexane/EtOAc 1:1). The reaction mixture is then washed twice with NH4Cl sat. solution and twice with NaHCO3 sat. solution. The organic layer is dried over Na2SO4, filtered and concentrated, to give 639 mg of an orange oil which is purified by flash chromatography (cyclohexane/EtOAc gradient, from 9/1 to 1/1 over 30 min). The title product is isolated as a slightly yellow solid (467.7 mg; 96%).
Wird geladen…