Tributylvinyltin → Ethyl 5-(pyridin-2-yl)-4-vinylisoxazole-3-carboxylate

HRID 1951948Notes

Reaction equation

HRID 1951948 reaction equation
Br[C:2]1[C:3]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[N:4][O:5][C:6]=1[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][N:8]=1.[CH2:18]([Sn](CCCC)(CCCC)C=C)[CH2:19]CC>O1CCOCC1.C(OCC)(=O)C.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.F[P-](F)(F)(F)(F)F.C([N+]1C=CN(C)C=1)CCC>[N:8]1[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=1[C:6]1[O:5][N:4]=[C:3]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[C:2]=1[CH:18]=[CH2:19]

Participants

7

Reactant 2

HCID 81998TributylvinyltinHCID 23006245Ethyl 4-bromo-5-(pyridin-2-yl)isoxazole-3-carboxylate

Product 1

HCID 58062830Ethyl 5-(pyridin-2-yl)-4-vinylisoxazole-3-carboxylateYield 414.3%

Reagents, catalysts & solvents 4

HCID 27341741-Butyl-3-methylimidazolium hexafluorophosphateCatalystHCID 178418476HCID 178418476, compoundCatalystHCID 8857Ethyl AcetateSolventHCID 312751,4-DioxaneSolvent

Procedure

A solution of ethyl 4-bromo-5-(pyridin-2-yl)isoxazole-3-carboxylate (2-C) (170 mg, 0.572 mmol), tributyl(vinyl)tin (0.504 mL, 1.72 mmol), dichlorobis(triphenylphosphine)-palladium(II) (24.1 mg, 0.034 mmol), and 1-butyl-3-methylimidazolium hexafluorophosphate (0.012 mL, 0.057 mmol) in dioxane (3 mL) was heated to 170° C. via microwave for 120 minutes. The reaction mixture was diluted with ethyl acetate (50 mL), washed with water (10 mL), washed with brine (10 mL), and dried over anhydrous sodium sulfate. Concentration gave a crude product which was purified by silica gel chromatography with hexanes/ethyl acetate (4/1) to give ethyl 5-(pyridin-2-yl)-4-vinylisoxazole-3-carboxylate (60 mg, 2.37 mmol, 41% yield). The compound had an HPLC retention time=2.80 min.—Column: YMC S5 COMBISCREEN® 4.6×50 mm; Gradient time: 4 min; Flow rate=4 ml/min; Solvent A=10% MeOH—90% Water—0.2% H3PO4; Solvent B=90% MeOH—10% water—0.2% H3PO4; Start % B=0; Final % B=100. LC-MS: M+1=245.2. 1H NMR (400 MHz, MeOD) δ ppm 1.42 (t, 3H), 4.47 (q, J=7.19 Hz, 2H), 5.49 (dd, J=11.80, 1.25 Hz, 1H), 5.85 (dd, J=18.07, 1.51 Hz, 1H), 7.26 (dd, J=18.07, 11.80 Hz, 1H), 7.51 (ddd, J=7.03, 5.02, 1.76 Hz, 1H), 7.93-8.02 (m, 2H), and 8.72-8.75 (m, 1H).

Workup

  1. washwashed with water (10 mL)
  2. washwashed with brine (10 mL)
  3. dry with materialdried over anhydrous sodium sulfate
  4. concentrationConcentration
  5. customgave a crude product which
  6. customwas purified by silica gel chromatography with hexanes/ethyl acetate (4/1)

Sources & evidence

ORD record
ord-296c276f8eb846f78d66144819e89441
Source dataset
uspto-grants-2013_03
Patent number
US08404672B2

Reaction notes

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