Tributylvinyltin → Ethyl 2-vinylthiazole-5-carboxylate

HRID 70902

Reaction equation

HRID 70902 reaction equation
[CH2:1]([Sn](CCCC)(CCCC)C=C)[CH2:2]CC.Br[C:17]1[S:18][C:19]([C:22]([O:24][CH2:25][CH3:26])=[O:23])=[CH:20][N:21]=1>O1CCOCC1.Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[CH:1]([C:17]1[S:18][C:19]([C:22]([O:24][CH2:25][CH3:26])=[O:23])=[CH:20][N:21]=1)=[CH2:2]

Participants

5

Reactant 2

HCID 81998TributylvinyltinHCID 3614103Ethyl 2-bromothiazole-5-carboxylate

Product 1

HCID 59607571Ethyl 2-vinylthiazole-5-carboxylateYield 89.8%

Reagents, catalysts & solvents 2

HCID 178418476HCID 178418476, compoundCatalystHCID 312751,4-DioxaneSolvent

Conditions

Temperature
100 °C

Procedure

To a solution of tributyl(vinyl)stannane (0.92 mL, 3.14 mmol) and ethyl 2-bromothiazole-5-carboxylate (0.38 mL, 2.54 mmol) in dioxane (33 mL) is added Pd(PPh3)2Cl2 (182 mg, 0.26 mmol) at room temperature. After stirring at 100° C. under nitrogen for 4 hours, the solution is cooled to ambient temperature and then quenched with H2O. The crude is diluted with EtOAc, the organic layer is washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The obtained residue is purified by flash column chromatography on silica gel (eluent: heptane/EtOAc=90:10 to 80:20) to give ethyl 2-vinylthiazole-5-carboxylate (418 mg). HPLC retention time=0.45 minutes (condition B); MS (m+1)=184.1; 1H NMR (400 MHz, CD3OD) δ ppm 1.37 (t, J=7.2 Hz, 3 H) 4.35 (q, J=7.1 Hz, 2 H) 5.71 (d, J=10.9 Hz, 1 H) 6.24 (d, J=17.4 Hz, 1 H) 6.93 (dd, J=17.4, 10.9 Hz, 1 H) 8.29 (s, 1 H)

Workup

  1. temperaturethe solution is cooled to ambient temperature
  2. customquenched with H2O
  3. additionThe crude is diluted with EtOAc
  4. washthe organic layer is washed with brine
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure
  8. customThe obtained residue is purified by flash column chromatography on silica gel (eluent: heptane/EtOAc=90:10 to 80:20)

Sources & evidence

ORD record
ord-dbd8097989f9421896e1ccd214e01c2b
Source dataset
uspto-grants-2014_09
Patent number
US08822534B2

Linked notes

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