Water → 3-ethenyl-6,7-dihydro-5H-pyrano[2,3-c]pyridazine

HRID 15150Notes

Reaction equation

HRID 15150 reaction equation
FC(F)(F)S(O[C:7]1[N:12]=[N:11][C:10]2[O:13][CH2:14][CH2:15][CH2:16][C:9]=2[CH:8]=1)(=O)=O.C(=O)([O-])[O-].[K+].[K+].O.[CH:26](B1OB(C=C)OB(C=C)O1)=[CH2:27]>COCCOC.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH:26]([C:7]1[N:12]=[N:11][C:10]2[O:13][CH2:14][CH2:15][CH2:16][C:9]=2[CH:8]=1)=[CH2:27]

Participants

7

Reactant 4

HCID 962WaterHCID 11430Potassium CarbonateHCID 2734807TrivinylboroxinHCID 866141506,7-dihydro-5H-pyrano[2,3-c]pyridazin-3-yl trifluoromethanesulfonate

Product 1

HCID 675268253-ethenyl-6,7-dihydro-5H-pyrano[2,3-c]pyridazineYield 77%

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 80711,2-DimethoxyethaneSolvent

Procedure

Argon was bubbled for 15 minutes through a solution of 6,7-dihydro-5H-pyrano[2,3-c]pyridazin-3-yl trifluoromethanesulfonate (228 mg, 0.8 mmol) in 1,2-dimethoxyethane (6.5 ml). Tetrakis(triphenylphosphine)palladium(0) (50 mg, 0.0435 mmol) was added and the solution stirred for 20 minutes under argon. The mixture was then treated with potassium carbonate (111 mg, 0.8 mmol), water (1.9 ml) and 2,4,6-trivinylcyclotriboroxane:pyridine complex (180 mg, 0.75 mmol) (for a preparation of this reagent see F. Kerins and D. F. O'Shea, J. Org. Chem. 2002, 67, 4968-4971). After stirring for 2 hours at 80° C., the mixture was cooled and partitioned between dichloromethane and saturated aqueous sodium bicarbonate solution. The layers were separated and the aqueous fraction was extracted twice with 20% methanol/dichloromethane. The combined organic solution was dried, evaporated and the residue chromatographed on silica gel, eluting with ethyl acetate to give product as a white solid (100 mg, 77%).

Workup

  1. custompyridine complex (180 mg, 0.75 mmol) (for a preparation of this reagent
  2. stirringAfter stirring for 2 hours at 80° C.
  3. temperaturethe mixture was cooled
  4. custompartitioned between dichloromethane and saturated aqueous sodium bicarbonate solution
  5. customThe layers were separated
  6. extractionthe aqueous fraction was extracted twice with 20% methanol/dichloromethane
  7. customThe combined organic solution was dried
  8. customevaporated
  9. customthe residue chromatographed on silica gel
  10. washeluting with ethyl acetate

Sources & evidence

ORD record
ord-14ae7afc5a144a529e619ec1e51e5c60
Source dataset
uspto-grants-2010_06
Patent number
US07732460B2

Reaction notes

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