Trifluoroacetic anhydride → 3-t-Butyl-4-Isopropoxy-3-cyclobutene-1,2-dione

HRID 1058850Notes

Reaction equation

HRID 1058850 reaction equation
[C:1]([Li])([CH3:4])([CH3:3])[CH3:2].C(O[C:10]1[C:11](=[O:19])[C:12](=[O:18])[C:13]=1[O:14][CH:15]([CH3:17])[CH3:16])(C)C.FC(F)(F)C(OC(=O)C(F)(F)F)=O.[NH4+].[Cl-]>CCCCC.C1COCC1.CCOC(C)=O>[C:1]([C:10]1[C:11](=[O:19])[C:12](=[O:18])[C:13]=1[O:14][CH:15]([CH3:16])[CH3:17])([CH3:4])([CH3:3])[CH3:2]

Participants

8

Reactant 4

HCID 9845Trifluoroacetic anhydrideHCID 25517Ammonium ChlorideHCID 1823143,4-Diisopropoxy-3-cyclobutene-1,2-dioneHCID 178418306HCID 178418306, compound

Product 1

HCID 110088553-t-Butyl-4-Isopropoxy-3-cyclobutene-1,2-dioneYield 69%

Reagents, catalysts & solvents 3

HCID 8003PentaneSolventHCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Procedure

tert-Butyl lithium (2.29 ml of a 1.7M solution in pentane, 3.9 mmol) was added to a solution of 3,4-diisopropoxy-3-cyclobutene-1,2-dione (594 mg, 3 mmol) in THF (30 ml) at −78° C. After 5 h trifluoroactic anhydride (636 μl, 4.5 mmol) was added and stirring continued at −78° C. for 30 min. The cold mixture was poured into NH4Cl(aq), extraced with EtOAc, dried (Na2SO4) and evaporated in vacuo. Column chromatography (SiO2; EtOAc/hexane, 15:85) gave the title compound as a mobile yellow oil (408 mg, 69%). δH (CDCl3) 5.43 (1H, sept, J 6.2 Hz), 1.45 (6H, d, J 6.2 Hz) and 1.33 (9H, s); m/z (ES+, 70V) 197 (M++H).

Workup

  1. dry with materialdried (Na2SO4)
  2. customevaporated in vacuo

Sources & evidence

ORD record
ord-6ea6a24e614347d58160163093db22ff
Source dataset
uspto-grants-2003_02
Patent number
US06518283B1

Reaction notes

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