Squaric acid → HCID 10935546, compound

HRID 1018770Notes

Reaction equation

HRID 1018770 reaction equation
[C:1]1([OH:8])[C:5](=O)[C:3](=[O:4])[C:2]=1[OH:7].[CH3:9][C:10]([C:13]1[O:14][C:15]([C:28]([CH3:31])([CH3:30])[CH3:29])=[CH:16][C:17](=[CH:19]C2C(Cl)(Cl)C(=O)C=2Cl)[CH:18]=1)([CH3:12])[CH3:11]>OS(C(F)(F)F)(=O)=O>[CH3:12][C:10]([C:13]1[O:14][C:15]([C:28]([CH3:31])([CH3:30])[CH3:29])=[CH:16][C:17](=[CH:19][C:5]2[C:3](=[O:4])[C:2](=[O:7])[C:1]=2[OH:8])[CH:18]=1)([CH3:9])[CH3:11]

Participants

4

Reactant 2

HCID 17913Squaric acidHCID 18402139HCID 18402139, compound

Product 1

HCID 10935546HCID 10935546, compoundYield 87%

Reagents, catalysts & solvents 1

HCID 62406Trifluoromethanesulfonic acidSolvent

Procedure

This Example illustrates the preparation, by a reaction analogous to D→E shown in FIG. 1, of the squaric acid derivative of Formula II in which Q1 is a 2,6-bis(1,1-dimethylethyl)-4-pyrylidene grouping and R1 is a hydrogen atom. 3-[2,6-Bis(1,1-dimethylethyl)-(4H-pyran-4-ylidene)-methyl]-2,4,4-tri-chlorocyclobut-2-en-1-one (100 mg, 0.27 mmole, prepared in Example 47 above), was dissolved in triflic acid (1 mL) and the resultant solution heated at 60° C. for 1 hour, 80° C. for a further 2 hours, and finally at 105° C. for 5 hours. The hot mixture was then poured over ice, and the resultant mixture stirred to give a solid precipitate. The mixture was extracted several times with dichloromethane, and the extracts were combined, washed with brine, dried over sodium sulfate and evaporated to dryness. The residue was redissolved in dichloromethane and applied to two preparative silica gel chromatography plates. Elution with 8% methanol in dichloromethane resulted in the development of many minor bands, with a major yellow band streaking from the origin. The major yellow band was extracted with methanol, the resultant solution evaporated to dryness, the residue dissolved in dichloromethane, and the solution filtered and evaporated to dryness. Pumping under high vacuum gave a yellow-brown solid (70 mg, 87% yield). The structure of the product was confirmed by proton NMR spectroscopy.

Workup

  1. customthe preparation
  2. customby a reaction analogous
  3. additionThe hot mixture was then poured over ice
  4. customto give a solid precipitate
  5. extractionThe mixture was extracted several times with dichloromethane
  6. washwashed with brine
  7. dry with materialdried over sodium sulfate
  8. customevaporated to dryness
  9. dissolutionThe residue was redissolved in dichloromethane
  10. washElution with 8% methanol in dichloromethane
  11. customresulted in the development of many minor bands, with a major yellow band streaking from the origin
  12. extractionThe major yellow band was extracted with methanol
  13. customthe resultant solution evaporated to dryness
  14. dissolutionthe residue dissolved in dichloromethane
  15. filtrationthe solution filtered
  16. customevaporated to dryness

Sources & evidence

ORD record
ord-43d533bc3778491fb1ba621f1a2b0678
Source dataset
uspto-grants-2002_11
Patent number
US06482950B1

Reaction notes

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