Potassium Carbonate → Ethyl 2-(3-methanesulphonylphenyl)thiazole-4-carboxylate

HRID 1695517Notes

Reaction equation

HRID 1695517 reaction equation
Br[C:2]1[S:3][CH:4]=[C:5]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[N:6]=1.[CH3:12][S:13]([C:16]1[CH:17]=[C:18](B(O)O)[CH:19]=[CH:20][CH:21]=1)(=[O:15])=[O:14].C(=O)([O-])[O-].[K+].[K+]>O1CCOCC1.C(N1C=CN(C(C)C)C1=[Pd-3](Cl)(Cl)C1C(Cl)=CC=CN=1)(C)C>[CH3:12][S:13]([C:16]1[CH:21]=[C:20]([C:2]2[S:3][CH:4]=[C:5]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[N:6]=2)[CH:19]=[CH:18][CH:17]=1)(=[O:15])=[O:14]

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 353965Ethyl 2-bromo-1,3-thiazole-4-carboxylateHCID 27735423-(Methylsulfonyl)phenylboronic acid

Product 1

HCID 67277205Ethyl 2-(3-methanesulphonylphenyl)thiazole-4-carboxylateYield 47.7%

Reagents, catalysts & solvents 2

HCID 178456358HCID 178456358, compoundCatalystHCID 312751,4-DioxaneSolvent

Procedure

Ethyl 2-bromothiazole-4-carboxylate (1 g), 3-(methylsulphonyl)phenyl-boronic acid (1.02 g, 1.2 equivalents) and potassium carbonate (1.76 g) are introduced in dioxane (12.5 ml). (1,3-Diisopropylimidazol-2-ylidene)(3-chloropyridyl)palladium(II) dichloride (288 mg) is added, and the mixture is stirred under reflux under protective gas for 18 h. Dioxane is then removed in a rotary evaporator, and the residue is taken up in ethyl acetate and water. The organic phase is separated off and the aqueous phase is back-extracted twice with ethyl acetate. The combined organic phases are washed with brine and dried over sodium sulphate and concentrated. Purification by column chromatography on silica gel (ethyl acetate/hexane) results in a white solid (629 mg).

Workup

  1. temperatureunder reflux under protective gas for 18 h
  2. customDioxane is then removed in a rotary evaporator
  3. customThe organic phase is separated off
  4. extractionthe aqueous phase is back-extracted twice with ethyl acetate
  5. washThe combined organic phases are washed with brine
  6. dry with materialdried over sodium sulphate
  7. concentrationconcentrated
  8. customPurification by column chromatography on silica gel (ethyl acetate/hexane)

Sources & evidence

ORD record
ord-75f1eea9453248d1a790e15de0fcd9c2
Source dataset
uspto-grants-2012_04
Patent number
US08163739B2

Reaction notes

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