Cesium carbonate → Ethyl 5-ethyl-2-(4-nitrophenyl)-1,3-oxazole-4-carboxylate

HRID 43583

Reaction equation

[CH2:1]([C:3]1[O:7][CH:6]=[N:5][C:4]=1[C:8]([O:10][CH2:11][CH3:12])=[O:9])[CH3:2].I[C:14]1[CH:19]=[CH:18][C:17]([N+:20]([O-:22])=[O:21])=[CH:16][CH:15]=1.CC1C=CC=CC=1P(C1C=CC=CC=1C)C1C=CC=CC=1C.C(=O)([O-])[O-].[Cs+].[Cs+]>C([O-])(=O)C.[Pd+2].C([O-])(=O)C.O.O1CCOCC1>[CH2:1]([C:3]1[O:7][C:6]([C:14]2[CH:19]=[CH:18][C:17]([N+:20]([O-:22])=[O:21])=[CH:16][CH:15]=2)=[N:5][C:4]=1[C:8]([O:10][CH2:11][CH3:12])=[O:9])[CH3:2]

Participants

Conditions

Temperature: 100 °C

Procedure

Dioxane (30 mL) was added to ethyl 5-ethyl-1,3-oxazole-4-carboxylate (described in Armarego, Wilfred L. F.; Taguchi, Hiroyasu; Cotton, Richard G. H.; Battiston, Sandra; Leong, Lillian; Eur. J. Med. Chem. Chim. Ther.; 22; 1987; 283-292, 1.69 g, 10 mmol), 1-iodo-4-nitrobenzene (2.74 g, 11 mmol), palladium acetate (179.6 mg, 0.8 mmol), tris(2-methylphenyl)phosphine (0.49 g, 1.6 mmol) and cesium carbonate (3.25 g, 10 mmol), and the mixture was stirred at 100° C. for 13 hours. Water was added, followed by extraction with ethyl acetate and washing with brine. This was dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=5/1, 3/1, 2/1) to obtain 1.08 g of the title compound as a colorless solid (37%).

Workup

extractionfollowed by extraction with ethyl acetate
washwashing with brine
dry with materialThis was dried over anhydrous magnesium sulfate
concentrationconcentrated under reduced pressure
customThe residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=5/1, 3/1, 2/1)

Sources & evidence

ORD record: ord-90ceebe8cc994cf6baf0a2a04633192b
Source dataset: uspto-grants-2013_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08536197B2

Linked notes

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