N-bromobutanimide → Ethyl 3-bromo-5-methylimidazo[1,2-a]pyridine-2-carboxylate

HRID 408788Notes

Reaction equation

[CH3:1][C:2]1[N:7]2[CH:8]=[C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[N:10]=[C:6]2[CH:5]=[CH:4][CH:3]=1.[Br:16]N1C(=O)CCC1=O>C(#N)C>[Br:16][C:8]1[N:7]2[C:2]([CH3:1])=[CH:3][CH:4]=[CH:5][C:6]2=[N:10][C:9]=1[C:11]([O:13][CH2:14][CH3:15])=[O:12]

Participants

Conditions

Temperature: 20 °C

Procedure

A solution of ethyl 5-methylimidazo[1,2-a]pyridine-2-carboxylate (5.0 g, 25 mmol) in acetonitrile (94 mL) was treated with N-bromosuccinimide (4.8 g, 27 mmol) in acetonitrile (47 mL) dropwise and stirred at 20° C. for 30 min. The reaction mixture was concentrated, diluted with dichloromethane (200 mL), and washed with saturated sodium bicarbonate (150 mL) and brine (50 mL). The organic layer was dried with sodium sulfate, filtered, and concentrated to a crude solid. Purification by flash column chromatography gave the desired product (4.0 g, 58%). LCMS for C11H12BrN2O2 (M+H)+: m/z=282.9, 284.9.

Workup

concentrationThe reaction mixture was concentrated
additiondiluted with dichloromethane (200 mL)
washwashed with saturated sodium bicarbonate (150 mL) and brine (50 mL)
dry with materialThe organic layer was dried with sodium sulfate
filtrationfiltered
concentrationconcentrated to a crude solid
customPurification by flash column chromatography

Sources & evidence

ORD record: ord-b14effa5a1504195b065abe57be9aa22
Source dataset: uspto-grants-2014_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08759359B2

Reaction notes

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