Citric Acid → 5-Bromo-2-chloro-1-(4-methoxycarbonyl-5-oxazolylmethyl)benzene

HRID 1625887Notes

Reaction equation

CC(C)([O-])C.[K+].[N+:7]([CH2:9][C:10]([O:12][CH3:13])=[O:11])#[C-:8].[Br:14][C:15]1[CH:16]=[CH:17][C:18]([Cl:25])=[C:19]([CH2:21][C:22](Cl)=[O:23])[CH:20]=1.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>O1CCCC1>[Br:14][C:15]1[CH:16]=[CH:17][C:18]([Cl:25])=[C:19]([CH2:21][C:22]2[O:23][CH:8]=[N:7][C:9]=2[C:10]([O:12][CH3:13])=[O:11])[CH:20]=1

Participants

Conditions

Temperature: 0 °C

Procedure

A solution of potassium t-butoxide (1.35 g) in tetrahydrofuran (20 ml) was cooled to 0° C., and thereto was added methyl isocyanoacetate (1.33 ml). Then, a solution of the above 5-bromo-2-chlorophenylacetyl chloride in tetrahydrofuran (20 ml) was added thereto, and the mixture was stirred at 0° C. for 2 hours, and then at room temperature overnight. The mixture was cooled again to 0° C. 10% aqueous citric acid solution was added thereto, and the mixture was extracted with ethyl acetate. The extract was washed with water and brine, and dried over sodium sulfate. The solvent was evaporated under reduced pressure and the residue was purified by silica gel column chromatography (hexane:ethyl acetate=3:1) to give 5-bromo-2-chloro-1-(4-methoxycarbonyl-5-oxazolylmethyl)benzene (1.12 g) as a yellow solid. APCI-Mass m/Z 330/332 (M+H).

Workup

customat room temperature
customovernight
temperatureThe mixture was cooled again to 0° C
extractionthe mixture was extracted with ethyl acetate
washThe extract was washed with water and brine
dry with materialdried over sodium sulfate
customThe solvent was evaporated under reduced pressure
customthe residue was purified by silica gel column chromatography (hexane:ethyl acetate=3:1)

Sources & evidence

ORD record: ord-ce431aa5c3394967838b3b93b3155dac
Source dataset: uspto-grants-2014_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08785403B2

Reaction notes

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