Potassium Carbonate → 3-Chloro-6-vinylpyridazine

HRID 1890966Notes

Reaction equation

HRID 1890966 reaction equation
[Cl:1][C:2]1[N:3]=[N:4][C:5](Cl)=[CH:6][CH:7]=1.[CH:9](B1OC(C)(C)C(C)(C)O1)=[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 52330122-Ethenyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

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 pinacol 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 3-chloro-6-vinyl-pyridazine 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-10f6dfcec3ef4457b469766398b6981d
Source dataset
uspto-grants-2013_08
Patent number
US08507489B2

Reaction notes

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