Stannane, tributyl(1-ethoxyethenyl)- → 2-Cyclopropyl-6-[1-(ethoxy)ethenyl]-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile

HRID 17336

Reaction equation

HRID 17336 reaction equation
Br[C:2]1[C:3]([F:17])=[C:4]2[O:8][C:7]([CH:9]3[CH2:11][CH2:10]3)=[N:6][C:5]2=[C:12]([C:15]#[N:16])[C:13]=1[CH3:14].C([Sn](CCCC)(CCCC)[C:23]([O:25][CH2:26][CH3:27])=[CH2:24])CCC>C1(C)C=CC=CC=1.Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C(C1(C)C(O)=C(C(C)(C)C)C=CC1)(C)(C)C>[CH:9]1([C:7]2[O:8][C:4]3[C:5](=[C:12]([C:15]#[N:16])[C:13]([CH3:14])=[C:2]([C:23]([O:25][CH2:26][CH3:27])=[CH2:24])[C:3]=3[F:17])[N:6]=2)[CH2:11][CH2:10]1

Participants

6

Reactant 2

HCID 619414Stannane, tributyl(1-ethoxyethenyl)-HCID 510414276-Bromo-2-cyclopropyl-7-fluoro-5-methylbenzoxazole-4-carbonitrile

Product 1

HCID 685864422-Cyclopropyl-6-[1-(ethoxy)ethenyl]-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrileYield 108.5%

Reagents, catalysts & solvents 3

HCID 666371922,6-Di-t-butylcresolCatalystHCID 178418476HCID 178418476, compoundCatalystHCID 1140TolueneSolvent

Procedure

6-Bromo-2-cyclopropyl-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile (I-77) (8.88 g, 30.08 mmol) was dissolved in toluene (130 ml), then tributyl(1-ethoxyvinyl)tin (11.2 ml, 33.09 mmol) and 2,6-di-tert-butylcresol (66 mg, 0.30 mmol) and bis(triphenylphosphine)palladium(II) dichloride (1.06 g, 1.50 mmol) were added, followed by heating under reflux for 17 hours under nitrogen atmosphere. The reaction liquid was cooled, the insoluble matter was separated by filtration through Celite, the solvent was concentrated under reduced pressure. The resulting residue was subjected to silica gel column chromatography, followed by removing tin-derived side products with n-hexane and by elution with a mixed solvent of n-hexane/ethyl acetate (7:1, v/v) to obtain the a crude product (9.34 g, quant.) as a yellow white solid.

Workup

  1. temperatureby heating
  2. temperatureunder reflux for 17 hours under nitrogen atmosphere
  3. customThe reaction liquid
  4. temperaturewas cooled
  5. customthe insoluble matter was separated by filtration through Celite
  6. concentrationthe solvent was concentrated under reduced pressure
  7. customby removing tin-
  8. washby elution with a mixed solvent of n-hexane/ethyl acetate (7:1

Sources & evidence

ORD record
ord-bc7ab6ec423e4978a7320d1f5439a7aa
Source dataset
uspto-grants-2010_06
Patent number
US07737166B2

Linked notes

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