Ammonium Chloride → 6-[(RS)-1-hydroxyethyl]-N-phenylimidazo[1,2-a]pyridine-2-carboxamide

HRID 1952213Notes

Reaction equation

[CH:1]([C:3]1[CH:4]=[CH:5][C:6]2[N:7]([CH:9]=[C:10]([C:12]([NH:14][C:15]3[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=3)=[O:13])[N:11]=2)[CH:8]=1)=[O:2].[CH3:21][Mg]Cl.[Cl-].[NH4+]>O1CCCC1.C(OCC)(=O)C>[OH:2][CH:1]([C:3]1[CH:4]=[CH:5][C:6]2[N:7]([CH:9]=[C:10]([C:12]([NH:14][C:15]3[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=3)=[O:13])[N:11]=2)[CH:8]=1)[CH3:21]

Participants

Conditions

Temperature: 5 °C

Procedure

A suspension of 150 mg of 6-formyl-N-phenylimidazo[1,2-a]pyridine-2-carboxamide in 10 ml of tetrahydrofuran is cooled to 5° C. 1.9 ml of a 3M solution of methylmagnesium chloride in tetrahydrofuran are added dropwise. The reaction mixture is stirred at 5° C. for 4 hours, then treated with 20 ml of a saturated ammonium chloride solution, stirred and then diluted with 30 ml of ethyl acetate. The aqueous phase is extracted with ethyl acetate and the combined organic phases are washed with a saturated sodium chloride solution, dried and concentrated to dryness under reduced pressure. After chromatographing on silica, elution being carried out with dichloromethane and then with mixtures of dichloromethane and ethyl acetate (85/15, then 60/40), the fractions comprising the expected product are combined and evaporated to dryness under reduced pressure to give 59 mg of 6-[(RS)-1-hydroxyethyl]-N-phenylimidazo[1,2-a]pyridine-2-carboxamide in the form of a white solid.

Workup

stirringstirred
extractionThe aqueous phase is extracted with ethyl acetate
washthe combined organic phases are washed with a saturated sodium chloride solution
customdried
concentrationconcentrated to dryness under reduced pressure
washAfter chromatographing on silica, elution
customevaporated to dryness under reduced pressure

Sources & evidence

ORD record: ord-05c4792f7f794c4fab5a92ec8e7a74e1
Source dataset: uspto-grants-2013_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08404848B2

Reaction notes

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