2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 2,4-Dichloro-5-methoxy-6-vinylpyrimidine

HRID 923676

Reaction equation

HRID 923676 reaction equation
[Cl:1][C:2]1[N:7]=[CH:6][C:5]([O:8][CH3:9])=[C:4]([Cl:10])[N:3]=1.[CH:11]([Mg]Br)=[CH2:12].ClC1C(=O)C(C#N)=C(C#N)C(=O)C=1Cl>O1CCCC1>[Cl:1][C:2]1[N:7]=[C:6]([CH:11]=[CH2:12])[C:5]([O:8][CH3:9])=[C:4]([Cl:10])[N:3]=1

Participants

5

Reactant 3

HCID 67752,3-Dichloro-5,6-dicyano-1,4-benzoquinoneHCID 6014012,4-Dichloro-5-methoxypyrimidineHCID 178418507HCID 178418507, compound

Product 1

HCID 866893262,4-Dichloro-5-methoxy-6-vinylpyrimidineYield 60%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of commercially available 2,6-dichloro-5-methoxy pyrimidine (100 g, 0.55 mol) in dry tetrahydrofuran was added, dropwise, 1M vinyl magnesium bromide in tetrahydrofuran solvent (124 g, 0.94 mol) over one hour (h) at room temperature. The mixture was then stirred for 4 h at room temperature. Excess Grignard reagent was quenched by addition of acetone (200 mL) while the temperature of the mixture was maintained at a temperature below 20° C. Thereafter, 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) (151 g, 0.67 mol) was added at once and stirred overnight. A yellow solid precipitated out. The solid was filtered and washed with ethyl acetate (500 mL). The filtrate was concentrated under reduced pressure and the resulting crude compound was diluted with ethyl acetate (2 L). The resulting undissolved, dark, semi-solid was separated by filtration using ethyl acetate. It was further concentrated under reduced pressure to provide a crude compound, which was purified by column chromatography. The compound was eluted with 5% to 10% ethyl acetate in hexane mixture to provide the title compound (70 g, 60%): mp 60-61° C.; 1H NMR (CDCl3) δ 3.99 (s, 3H), 5.85 (d, 1H), 6.75 (d, 1H), 6.95 (dd, 1H).

Workup

  1. customExcess Grignard reagent was quenched by addition of acetone (200 mL) while the temperature of the mixture
  2. temperaturewas maintained at a temperature below 20° C
  3. stirringstirred overnight
  4. customA yellow solid precipitated out
  5. filtrationThe solid was filtered
  6. washwashed with ethyl acetate (500 mL)
  7. concentrationThe filtrate was concentrated under reduced pressure
  8. additionthe resulting crude compound was diluted with ethyl acetate (2 L)
  9. customThe resulting undissolved, dark, semi-solid was separated by filtration
  10. concentrationIt was further concentrated under reduced pressure
  11. customto provide a crude compound, which
  12. customwas purified by column chromatography
  13. washThe compound was eluted with 5% to 10% ethyl acetate in hexane mixture

Sources & evidence

ORD record
ord-9ef0a967c12a4b9c8b00f01a0ee0bef0
Source dataset
uspto-grants-2016_03
Patent number
US09278985B2

Linked notes

Loading…