6-Bromo-2,2-dimethyl-2H-chromene → 2-(4-benzyloxy-3,5-dimethoxy-phenyl)-1-(2,2-dimethyl-2H-chromen-6-yl)-ethanone

HRID 1724000Notes

Reaction equation

HRID 1724000 reaction equation
Br[C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][C:7]([CH3:13])([CH3:12])[CH:6]=[CH:5]2.[Li]CCCC.[CH2:19]([O:26][C:27]1[C:32]([O:33][CH3:34])=[CH:31][C:30]([CH2:35][CH:36]=[O:37])=[CH:29][C:28]=1[O:38][CH3:39])[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1>C1COCC1>[CH2:19]([O:26][C:27]1[C:32]([O:33][CH3:34])=[CH:31][C:30]([CH2:35][C:36]([C:2]2[CH:3]=[C:4]3[C:9](=[CH:10][CH:11]=2)[O:8][C:7]([CH3:13])([CH3:12])[CH:6]=[CH:5]3)=[O:37])=[CH:29][C:28]=1[O:38][CH3:39])[C:20]1[CH:21]=[CH:22][CH:23]=[CH:24][CH:25]=1

Participants

5

Reactant 3

HCID 117705336-Bromo-2,2-dimethyl-2H-chromeneHCID 57436872(4-Benzyloxy-3,5-dimethoxy-phenyl)-acetaldehydeHCID 178418339Butyllithium

Product 1

HCID 575584302-(4-benzyloxy-3,5-dimethoxy-phenyl)-1-(2,2-dimethyl-2H-chromen-6-yl)-ethanoneYield 20%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

To a cooled (−78° C.) stirring solution of 6-bromo-2,2-dimethyl-2H-chromene, which was prepared according to Chemistry and Biology, 2000, Vol. 7, p. 979, (567.7 mg, 2.38 mmol) in THF (7 mL) was added n-BuLi (2.88 M, 0.94 mL, 2.71 mmol). After completion of addition, the reaction mixture continued to stir at −78° C. After 25 minutes, (4-benzyloxy-3,5-dimethoxy-phenyl)-acetaldehyde (619.6 mg, 2.17 mmol) dissolved in THF (7.0 mL) was added. After completion of addition the reaction continued to stir for 15 minutes and was then quenched with saturated ammonium chloride. The aqueous layer was separated and extracted with ethyl acetate. All Combined organic layers were dried over sodium sulfate, filtered, and concentrated to yield a crude oil. The crude material was purified by silica gel chromatography (3:1 ethyl acetate:hexanes) to yield the desired product (200.5 mg, 20% yield).

Workup

  1. customwas prepared
  2. additionAfter completion of addition
  3. additionwas added
  4. additionAfter completion of addition the reaction
  5. stirringto stir for 15 minutes
  6. customwas then quenched with saturated ammonium chloride
  7. customThe aqueous layer was separated
  8. extractionextracted with ethyl acetate
  9. dry with materialwere dried over sodium sulfate
  10. filtrationfiltered
  11. concentrationconcentrated
  12. customto yield a crude oil
  13. customThe crude material was purified by silica gel chromatography (3:1 ethyl acetate:hexanes)

Sources & evidence

ORD record
ord-eae5545e2ba14d95830ebe19920ac96b
Source dataset
uspto-grants-2009_02
Patent number
US07485283B2

Reaction notes

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