Trifluoroacetic anhydride → 3-Butyl-4-methoxycyclobut-3-ene-1,2-dione

HRID 1058857Notes

Reaction equation

HRID 1058857 reaction equation
[Li][CH2:2][CH2:3][CH2:4][CH3:5].[CH3:6][O:7][C:8]1[C:9](=O)[C:10](=[O:14])[C:11]=1[O:12]C.FC(F)(F)C(OC(=O)C(F)(F)F)=O.[NH4+].[Cl-]>CCCCCC.C1COCC1.CCOC(C)=O>[CH2:2]([C:9]1[C:10](=[O:14])[C:11](=[O:12])[C:8]=1[O:7][CH3:6])[CH2:3][CH2:4][CH3:5]

Participants

8

Reactant 4

HCID 9845Trifluoroacetic anhydrideHCID 25517Ammonium ChlorideHCID 1232273-Cyclobutene-1,2-dione, 3,4-dimethoxy-HCID 178418339Butyllithium

Product 1

HCID 136587053-Butyl-4-methoxycyclobut-3-ene-1,2-dioneYield 48%

Reagents, catalysts & solvents 3

HCID 8028TetrahydrofuranSolventHCID 8058HexaneSolventHCID 8857Ethyl AcetateSolvent

Procedure

n-BuLi (8.13 ml of a 1.6M solution in hexane, 13 mmol) was added slowly to a solution of 3,4-dimethoxy-3-cyclobutene-1,2-dione (1.42 g, 10 mmol) in THF (100 ml) at −78°. After 2 h, trifluoroacetic anhydride (2.12 ml, 15 mmol) was added. After a further 30 min the cold solution was poured into NH4Cl(aq) (100 ml) and EtOAc (100 ml) and stirred well. The aqueous layer was extracted with EtOAc. The organic extracts were washed with brine, dried (Na2SO4) and concentrated in vacuo. Column chromatography (SiO2, EtOAc/hexane, 30:70) gave the title compound as a yellow oil (803 mg, 48%). δH (CDCl3) 4.42 (3H, s), 2.60 (2H, t, J 7.6 Hz), 1.71-1.61 (2H, m), 1.44-1.32 (2H, m), 0.94 (3H, t, J 7.3 Hz). m/z (ES+, 70V) 169 (MH+).

Workup

  1. extractionThe aqueous layer was extracted with EtOAc
  2. washThe organic extracts were washed with brine
  3. dry with materialdried (Na2SO4)
  4. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-1e42c346cdba444c9cdf4f2c68eced3d
Source dataset
uspto-grants-2003_02
Patent number
US06518283B1

Reaction notes

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