Cesium fluoride → 1,4-Dimethyl-2-nitro-5-vinylbenzene

HRID 536396Notes

Reaction equation

HRID 536396 reaction equation
Br[C:2]1[CH:7]=[C:6]([CH3:8])[C:5]([N+:9]([O-:11])=[O:10])=[CH:4][C:3]=1[CH3:12].[CH:13](B(OCCCC)OCCCC)=[CH2:14].[F-].[Cs+]>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.COCCOC.CO>[CH3:8][C:6]1[CH:7]=[C:2]([CH:13]=[CH2:14])[C:3]([CH3:12])=[CH:4][C:5]=1[N+:9]([O-:11])=[O:10]

Participants

6

Reactant 3

HCID 25953Cesium fluorideHCID 236543Dibutyl Vinylboronate (stabilized with Phenothiazine)HCID 8258081-Bromo-2,5-dimethyl-4-nitrobenzene

Product 1

HCID 671554491,4-Dimethyl-2-nitro-5-vinylbenzene

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 86595564Dimethoxyethane methanolSolvent

Conditions

Temperature
130 °C

Procedure

To a microwave reaction vessel was added a mixture of 1-bromo-2,5-dimethyl-4-nitrobenzene (1.15 g, 5.0 mmol), dibutyl vinylboronate (1.16 g, 6.3 mmol), Pd(PPh3)4(289 mg, 0.25 mmol), CsF (2.28 g, 15 mmol) and a mixed solvent (1,2-dimethoxyethane/MeOH=2:1, 15 mL). The mixture was degassed and sealed with N2. The reaction vessel was then heated to 130° C. in a microwave reactor for 15 min. After opening the reaction vessel, the mixture was poured into saturated NH4Cl aqueous solution (30 mL) and extracted with EtOAc (3×50 mL). The combined organic layers were washed with brine and dried (MgSO4). After removing the drying agent by filtration, the filtrate was concentrated and purified by flash column chromatography (silica gel, 0-30% EtOAc in hexanes gradient) to provide 1,4-dimethyl-2-nitro-5-vinylbenzene as needlelike crystals; ESMS m/z 178.1 (M+H+).

Workup

  1. customTo a microwave reaction vessel
  2. additionwas added
  3. customThe mixture was degassed
  4. customsealed with N2
  5. additionthe mixture was poured into saturated NH4Cl aqueous solution (30 mL)
  6. extractionextracted with EtOAc (3×50 mL)
  7. washThe combined organic layers were washed with brine
  8. dry with materialdried (MgSO4)
  9. customAfter removing the drying agent
  10. filtrationby filtration
  11. concentrationthe filtrate was concentrated
  12. custompurified by flash column chromatography (silica gel, 0-30% EtOAc in hexanes gradient)

Sources & evidence

ORD record
ord-10698b50dd2f488aab6c0a01cc4b2397
Source dataset
uspto-grants-2014_10
Patent number
US08859574B2

Reaction notes

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