N-Iodosuccinimide → Ethyl 3-iodoimidazo[1,2-a]pyridine-2-carboxylate
Reaction equation
[N:1]1[C:2]([C:10]([O:12][CH2:13][CH3:14])=[O:11])=[CH:3][N:4]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=12.[I:15]N1C(=O)CCC1=O>C(#N)C>[I:15][C:3]1[N:4]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]2=[N:1][C:2]=1[C:10]([O:12][CH2:13][CH3:14])=[O:11]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
2.405 g (12.16 mmol) of ethyl imidazo[1,2-a]pyridine-2-carboxylate were dissolved in 60 ml of acetonitrile with magnetic stirring, to this solution were added 3.01 g (13.38 mmol) of N-iodosuccinimide. The mixture was stirred at r.t. for 1 h. The reaction mixture was treated with 50 ml of 100 mg/ml Na2S2O5 aqueous solution. The aqueous phase was extracted with 2×100 ml of ethyl acetate. The aqueous phase was neutralized by adding NaHCO3 portionwise and then extracted with 3×100 ml of ethyl acetate. The whole of the organic phases was combined and then washed with 200 ml of a saturated NaCl aqueous solution, and then dried on Na2SO4 which was then removed by filtration. The obtained filtrate was concentrated in vacuo in order to obtain 1.59 g (yield=41%) of ethyl 3-iodoimidazo[1,2-a]pyridine-2-carboxylate as a pale yellow solid. LC-MS: m/z=317 (MH+); UV purity at 254 nm=99%. 1H NMR (300 MHz, DMSO) δ 8.45 (d, J=6.9 Hz, 1H), 7.66 (d, J=9.1 Hz, 1H), 7.46 (d, J=7.0 Hz, 1H), 7.15 (d, J=6.6 Hz, 1H), 4.30 (d, J=7.1 Hz, 2H), 1.36 (d, J=7.1 Hz, 3H).
Workup
- extractionThe aqueous phase was extracted with 2×100 ml of ethyl acetate
- additionby adding NaHCO3 portionwise
- extractionextracted with 3×100 ml of ethyl acetate
- washwashed with 200 ml of a saturated NaCl aqueous solution
- customdried on Na2SO4 which
- customwas then removed by filtration
- concentrationThe obtained filtrate was concentrated in vacuo in order
Sources & evidence
- ORD record
- ord-fd8bfe76c58d41b184be4ce86ded97db
- Source dataset
- uspto-grants-2016_07
- Patent number
- US09381191B2
Reaction notes
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