Ethyl Bromide → (Imidazo[1,2-a]pyridin-5-yl)oxoacetic Acid Ethyl Ester
Reaction equation
Br[C:2]1[N:7]2[CH:8]=[CH:9][N:10]=[C:6]2[CH:5]=[CH:4][CH:3]=1.BrCC.[C:14](OCC)(=[O:20])[C:15]([O:17][CH2:18][CH3:19])=[O:16]>O1CCCC1>[CH2:18]([O:17][C:15](=[O:16])[C:14]([C:2]1[N:7]2[CH:8]=[CH:9][N:10]=[C:6]2[CH:5]=[CH:4][CH:3]=1)=[O:20])[CH3:19]Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -15 °C
Procedure
Add Mg turnings (0.25 g, 9.95 mmol) to a solution of 5-Bromoimidazo[1,2-a]pyridine (1.5 g, 7.65 mmol) in tetrahydrofuran (20 ml). Heat the reaction to 60° C. and add bromoethane (1.2 ml, 11.1 mmol). Reflux for another 0.5 hours, cool and cannula dropwise into a solution of diethyl oxalate (5 ml) in tetrahydrofuran (5 ml) at −15° C. Stir at −15° C. for 0.5 hours and at room temperature for 0.5 hours. Quench the reaction by adding pH 7 buffer, extract into ethyl acetate, wash with saturated sodium chloride, dry over magnesium sulfate, and concentrate under reduced pressure. Purification by flash chromatography, eluting with ethyl acetate:hexane: methanol gradient gives the title compound as a light brown oil.
Workup
- temperatureHeat
- customthe reaction to 60° C.
- temperatureReflux for another 0.5 hours
- temperaturecool
- customat −15° C
- customQuench
- customthe reaction
- additionby adding pH 7 buffer
- extractionextract into ethyl acetate
- washwash with saturated sodium chloride
- dry with materialdry over magnesium sulfate
- concentrationconcentrate under reduced pressure
- customPurification by flash chromatography
- washeluting with ethyl acetate
Sources & evidence
- ORD record
- ord-9db224d935324bbaaf6c2241e8c6f0f2
- Source dataset
- uspto-grants-2011_11
- Patent number
- US08058425B2
Reaction notes
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