Potassium Carbonate → 3-Chloro-6-vinylpyridazine

HRID 655257Notes

Reaction equation

HRID 655257 reaction equation
[Cl:1][C:2]1[N:3]=[N:4][C:5](Cl)=[CH:6][CH:7]=1.[CH:9](B(O)O)=[CH2:10].C(=O)([O-])[O-].[K+].[K+].O1CCOCC1>C1C=CC([PH+]([C]2[CH][CH][CH][CH]2)C2C=CC=CC=2)=CC=1.C1C=CC([PH+]([C]2[CH][CH][CH][CH]2)C2C=CC=CC=2)=CC=1.C(Cl)Cl.Cl[Pd]Cl.[Fe].O>[Cl:1][C:2]1[N:3]=[N:4][C:5]([CH:9]=[CH2:10])=[CH:6][CH:7]=1

Participants

7

Reactant 4

HCID 11430Potassium CarbonateHCID 312751,4-DioxaneHCID 673313,6-DichloropyridazineHCID 4683185Vinylboronic acid

Product 1

HCID 223362693-Chloro-6-vinylpyridazineYield 92%

Reagents, catalysts & solvents 2

HCID 53485975CID 53485975CatalystHCID 962WaterSolvent

Conditions

Temperature
80 °C

Procedure

A mixture of 3,6-dichloropyridazine (6 g, 40.3 mmol), vinyl boronic acid pinnacol ester (6.21 g, 6.83 mL, 40.3 mmol), potassium carbonate (120 mmol, 16.7 g), 1,4-dioxane (60 mL) and water (24 mL) was degassed for 15 min with nitrogen gas. Dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium(II) dichloromethane adduct (0.4 mmol, 292 mg) was then added and the mixture heated to 80° C. for 4 hours. The aqueous phase was then removed via pipette and the organic phase concentrated onto silica gel and purified via flash column chromatography (SiO2, hexane:ethyl acetate 100:0-60:40) to return the title compound as a white solid (5.2 g, 92% yield). 1H NMR (CDCl3): δ 5.75 (1H, d), 6.25 (1H, d), 7.05 (1H, dd), 7.49 (1H, d), 7.59 (1H, d). MS m/z=141 (M+H+)+.

Workup

  1. customwas degassed for 15 min with nitrogen gas
  2. customThe aqueous phase was then removed via pipette
  3. concentrationthe organic phase concentrated onto silica gel
  4. custompurified via flash column chromatography (SiO2, hexane:ethyl acetate 100:0-60:40)

Sources & evidence

ORD record
ord-c960ad76935c4fe3a9da369c2fad3307
Source dataset
uspto-grants-2011_12
Patent number
US08071581B2

Reaction notes

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