Cesium carbonate → 3-(4-Bromo-thiophen-2-yl)-oxazolidin-2-one

HRID 1436458Notes

Reaction equation

HRID 1436458 reaction equation
CN(CC)C.Br[C:7]1[S:8][CH:9]=[C:10]([Br:12])[CH:11]=1.[O:13]1[CH2:17][CH2:16][NH:15][C:14]1=[O:18].C(=O)([O-])[O-].[Cs+].[Cs+]>O1CCOCC1.[Cu]I>[Br:12][C:10]1[CH:11]=[C:7]([N:15]2[CH2:16][CH2:17][O:13][C:14]2=[O:18])[S:8][CH:9]=1

Participants

7

Reactant 4

HCID 10796Cesium carbonateHCID 11723DimethylethylamineHCID 739492-OxazolidinoneHCID 2724560Thiophene, 2,4-dibromo-

Product 1

HCID 688581893-(4-Bromo-thiophen-2-yl)-oxazolidin-2-oneYield 15.5%

Reagents, catalysts & solvents 2

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 312751,4-DioxaneSolvent

Conditions

Temperature
110 °C

Procedure

N,N-Dimethylethylamine (0.22 mL, 2.0 mmol), 2,4-dibromothiophene (5.0 g, 20.6 mmol) and oxazolidinone (2.1 g, 24.8 mmol) were added to a mixture of copper(I) iodide (0.39 g, 2.0 mmol) and cesium carbonate (13.4 g, 41.3 mmol) in dry dioxane under nitrogen. The reaction mixture was stirred at 110° C. for 16 h. The reaction was filtered through the Celite™ reagent and rinsed with methylene chloride. The filtrate was concentrated in vacuo to a residue. Purification of the crude product on silica gel using a stepwise gradient of 6:1 to 3:1 hexane:ethyl acetate as the eluent gave 3-(4-bromo-thiophen-2-yl)-oxazolidin-2-one (790 mg, 15%) as the desired product contaminated with 10% of the 3-(5-bromo-thiophen-3-yl)-oxazolidin-2-one isomer. MS (ES) m/z 249 [M+H]+.

Workup

  1. filtrationThe reaction was filtered through the Celite™ reagent
  2. washrinsed with methylene chloride
  3. concentrationThe filtrate was concentrated in vacuo to a residue
  4. customPurification of the crude product on silica gel using a stepwise gradient of 6:1 to 3:1 hexane

Sources & evidence

ORD record
ord-356b0aa7f59b45f1a40e5ca263868add
Source dataset
uspto-grants-2009_11
Patent number
US07618990B2

Reaction notes

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