Chloroacetaldehyde → Ethyl 5-amino-6-chloroimidazo[1,2-a]pyridine-8-carboxylate

反応式

[NH2:1][C:2]1[N:12]=[C:11]([NH:13]C(=O)C(C)(C)C)[C:10]([Cl:20])=[CH:9][C:3]=1[C:4]([O:6][CH2:7][CH3:8])=[O:5].Cl[CH2:22][CH:23]=O.C>C(O)C>[NH2:13][C:11]1[N:12]2[CH:22]=[CH:23][N:1]=[C:2]2[C:3]([C:4]([O:6][CH2:7][CH3:8])=[O:5])=[CH:9][C:10]=1[Cl:20]

参加物

実験手順

To a solution of ethyl 2-amino-5-chloro-6-[(2,2-dimethylpropanoyl)amino]nicotinate (Example 1, METHOD A, Step 2, 685 mg, 2.12 mmol) in ethanol (10 mL) was added 50% aqueous chloroacetaldehyde (430 μL, 3.4 mmol), and the mixture was refluxed with stirring overnight. The mixture was treated with charcoal and filtered. The filtrate was dry-loaded onto silica gel and chromatographed on a column of silica gel eluting with dichloromethane/methanol/25% aqueous ammonia (97:3:1 to 95:5:0.5) to give 220 mg (40%) of the title compound as a white solid.