Réaction #43449

Équation de réaction

3-chloro-6,7-dihydro[1,4]dioxino[2,3-c]pyridazine

dimethoxyethane

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product

Rendement 50.0%

3-Ethenyl-6,7-dihydro[1,4]dioxino[2,3-c]pyridazine

Rendement 50.0%

Conditions de réaction

Traitement

1. 1
   Autrewas degassed under argon for 10 min
2. 2
   workup.ADDITIONtetrakis(triphenylphosphine)palladium (0) (2 g), potassium carbonate (10.33 g), 2,4,6-trivinylcyclotriboroxane pyridine complex (11.32 g) and water (55 ml) were added
3. 3
   Températurecooled
4. 4
   Autreevaporated to dryness
5. 5
   workup.ADDITIONThe mixture was treated with aqueous sodium bicarbonate solution
6. 6
   Extractionextracted (5×) with DCM
7. 7
   SéchageExtracts were dried (sodium sulphate)
8. 8
   Autreevaporated
9. 9
   Autrethe residue chromatographed on silica gel (500 g)
10. 10
    Lavageeluting with 0-100% ethyl acetate-hexane

Mode opératoire

A solution of 3-chloro-6,7-dihydro[1,4]dioxino[2,3-c]pyridazine (13.6 g, 0.079 mol) containing ca. 15% of a bromo species in dimethoxyethane (400 ml) was degassed under argon for 10 min then tetrakis(triphenylphosphine)palladium (0) (2 g), potassium carbonate (10.33 g), 2,4,6-trivinylcyclotriboroxane pyridine complex (11.32 g) and water (55 ml) were added. The mixture was heated at 95° C. for 48 hours and cooled and evaporated to dryness. The mixture was treated with aqueous sodium bicarbonate solution and extracted (5×) with DCM. Extracts were dried (sodium sulphate), evaporated and the residue chromatographed on silica gel (500 g), eluting with 0-100% ethyl acetate-hexane, affording the product (6.43 g, 50%); [also some impure fractions (1.8 g)].

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