Water → 2-(5-Amino-6-benzyl-3-vinylpyrazin-2-yl)-5-methoxybenzaldehyde

HRID 526784Notes

Reaction equation

HRID 526784 reaction equation
[NH2:1][C:2]1[N:3]=[C:4](Cl)[C:5]([C:15]2[CH:22]=[CH:21][C:20]([O:23][CH3:24])=[CH:19][C:16]=2[CH:17]=[O:18])=[N:6][C:7]=1[CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.[CH2:26]([Sn](CCCC)(CCCC)C=C)[CH2:27]CC.O>C1(C)C=CC=CC=1.[Cl-].C([N+](CCCC)(CCCC)CCCC)CCC.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>[NH2:1][C:2]1[N:3]=[C:4]([CH:26]=[CH2:27])[C:5]([C:15]2[CH:22]=[CH:21][C:20]([O:23][CH3:24])=[CH:19][C:16]=2[CH:17]=[O:18])=[N:6][C:7]=1[CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1

Participants

7

Reactant 3

HCID 962WaterHCID 81998TributylvinyltinHCID 866706772-(5-Amino-6-benzyl-3-chloropyrazin-2-yl)-5-methoxybenzaldehyde

Product 1

HCID 866706782-(5-Amino-6-benzyl-3-vinylpyrazin-2-yl)-5-methoxybenzaldehydeYield 55.7%

Reagents, catalysts & solvents 3

HCID 70681Tetrabutylammonium ChlorideCatalystHCID 178418476HCID 178418476, compoundCatalystHCID 1140TolueneSolvent

Conditions

Temperature
110 °C

Procedure

Under an argon atmosphere, to a solution of 2-(5-amino-6-benzyl-3-chloropyrazin-2-yl)-5-methoxybenzaldehyde (7) (2.28 g, 6.44 mmol) in deaerated toluene (30 mL) were successively added dichlorobis(triphenylphosphine)palladium (II) (226 mg, 322 μmol), tributyl(vinyl)tin (3.75 mL, 12.8 mmol) and tetra-n-butylammonium chloride (3.50 g, 12.6 mmol) at room temperature. The mixture was heated to reflux for 1.5 hours (oil bath temperature at 110° C.). After cooling to room temperature, to the mixture was added water and the product was extracted with ethyl acetate (×3). The combined organic extract was washed successively with water (×1) and brine (×1) followed by drying over anhydrous sodium sulfate. After filtration and concentration under reduced pressure, the residue was purified by silica gel flash column chromatography (silica gel mixed with 10 wt % potassium fluoride, n-hexane/ethyl acetate=3/1) to give 2-(5-amino-6-benzyl-3-vinylpyrazin-2-yl)-5-methoxybenzaldehyde (8) (1.24 g, 3.59 mmol, 55.5%) as a reddish brown oily substance. TLC Rf=0.27 (n-hexane/ethyl acetate=3/1); 1H NMR (500 MHz, CDCl3) δ 3.92 (s, 3H), 4.15 (s, 2H), 4.50 (s, 2H), 5.39 (dd, 1H, J=2.0, 11.0 Hz), 6.33 (dd, 1H, J=2.0, 17.0 Hz), 6.57 (dd, 1H, J=11.0, 17.0 Hz), 7.20-7.28 (m, 4H), 7.30-7.36 (m, 2H), 7.41 (d, 1H, J=8.5 Hz), 7.55 (d, 1H, J=3.0 Hz), 9.88 (s, 1H); 13C NMR (126 MHz, CDCl3) δ 41.0, 55.7, 110.6, 120.5, 121.0, 127.2, 128.5 (2C), 129.1 (2C), 132.3, 132.9, 134.4, 136.1, 136.5, 138.7, 140.2, 145.2, 151.5, 159.8, 191.5.

Workup

  1. customat room temperature
  2. temperatureThe mixture was heated
  3. temperatureAfter cooling to room temperature, to the mixture
  4. extractionthe product was extracted with ethyl acetate (×3)
  5. extractionThe combined organic extract
  6. washwas washed successively with water (×1) and brine (×1)
  7. dry with materialby drying over anhydrous sodium sulfate
  8. filtrationAfter filtration and concentration under reduced pressure
  9. customthe residue was purified by silica gel flash column chromatography (silica gel mixed with 10 wt % potassium fluoride, n-hexane/ethyl acetate=3/1)

Sources & evidence

ORD record
ord-1fba47ce3cd748e6b40808cb1d1c636c
Source dataset
uspto-grants-2016_05
Patent number
US09346767B2

Reaction notes

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