N-Iodosuccinimide → Methyl 3-iodoimidazo[1,2-a]pyridine-8-carboxylate
Reaction equation
[CH3:1][O:2][C:3]([C:5]1[C:6]2[N:7]([CH:11]=[CH:12][N:13]=2)[CH:8]=[CH:9][CH:10]=1)=[O:4].[I:14]N1C(=O)CCC1=O>C(#N)C>[CH3:1][O:2][C:3]([C:5]1[C:6]2[N:7]([C:11]([I:14])=[CH:12][N:13]=2)[CH:8]=[CH:9][CH:10]=1)=[O:4]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A mixture of imidazo[1,2-a]pyridine-8-carboxylic acid methyl ester (3.24 g, 18.3 mmol) and N-iodosuccinimide (NIS) (4.11 g, 18.3 mmol) in acetonitrile (50 mL) is stirred at room temperature. After 2 hours, the reaction mixture is quenched with saturated aqueous Na2S2O3 and extracted with EtOAc (3×100 mL). The combined organic layers are washed with water, brine, dried over Na2SO4 and concentrated. The crude material is purified by silica gel chromatography eluting with 80% EtOAc in hexanes to afford 3-iodo-imidazo[1,2-a]pyridine-8-carboxylic acid methyl ester. Mp: 99-110° C.