1-Bromo-4-fluorobenzene → 1-(4-Fluorophenyl)but-2-en-1-one

HRID 2037461Notes

Reaction equation

HRID 2037461 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([F:8])=[CH:4][CH:3]=1.[Li]CCCC.[Li+].[Cl-].[C:16](Cl)(=[O:20])/[CH:17]=[CH:18]/[CH3:19]>C1COCC1.Cl[Cu]>[F:8][C:5]1[CH:6]=[CH:7][C:2]([C:16](=[O:20])[CH:17]=[CH:18][CH3:19])=[CH:3][CH:4]=1

Participants

7

Reactant 4

HCID 99931-Bromo-4-fluorobenzeneHCID 433294Lithium ChlorideHCID 643131trans-Crotonyl chlorideHCID 178418339Butyllithium

Product 1

HCID 668564531-(4-Fluorophenyl)but-2-en-1-oneYield 10%

Reagents, catalysts & solvents 2

HCID 62652Cuprous chlorideCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of 1-bromo-4-fluorobenzene (28 g, 0.162 mol) in THF (90 mL) was added n-BuLi (70 mL, 2.5 M) at −78° C. and stirred for 1 h under nitrogen. Then to a premixed solution of CuCl (18 g, 0.16 mol) and LiCl (15 g, 0.354 mol) in THF (160 mL) at −78° C. was added the above solution quickly. The formed solution was stirred for 20 minutes, and was treated with crotonyl chloride (21 g, 0.176 mol). The resulting solution was stirred for 30 minutes. The mixture was quenched with aq NH4Cl, the organic phase was separated, concentrated to give the crude product which was purified by column chromatography to afford 1-(4-fluorophenyl)but-2-en-1-one (2.6 g, 10%). 1H NMR (400 MHz, CDCl3): δ=2.02 (d, 3H), 6.88 (m, 1H), 7.10 (m, 3H), 7.98 (m, 2H).

Workup

  1. stirringThe formed solution was stirred for 20 minutes
  2. stirringThe resulting solution was stirred for 30 minutes
  3. customThe mixture was quenched with aq NH4Cl
  4. customthe organic phase was separated
  5. concentrationconcentrated
  6. customto give the crude product which
  7. customwas purified by column chromatography

Sources & evidence

ORD record
ord-cb208c1845844655a2129863bb0be18d
Source dataset
uspto-grants-2013_11
Patent number
US08575156B2

Reaction notes

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