Sulfuric Acid → HCID 66823800, compound

HRID 1193249Notes

Reaction equation

HRID 1193249 reaction equation
S(=O)(=O)(O)O.[Br:6][C:7]1[CH:8]=[CH:9][C:10]([O:25][CH:26]([F:28])[F:27])=[C:11]([CH:13]2[C:15]3([C:19](=[O:20])[C:18]([CH3:22])([CH3:21])[O:17][C:16]3([CH3:24])[CH3:23])[O:14]2)[CH:12]=1>ClCCCl>[Br:6][C:7]1[CH:8]=[CH:9][C:10]([O:25][CH:26]([F:27])[F:28])=[C:11]([CH:13]2[C:19](=[O:20])[C:18]([CH3:22])([CH3:21])[O:17][C:16]([CH3:24])([CH3:23])[C:15]2=[O:14])[CH:12]=1

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 86663676HCID 86663676, compound

Product 1

HCID 66823800HCID 66823800, compoundYield 29.5%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Conditions

Temperature
0 °C

Procedure

To an ice-cold solution of concentrated sulphuric acid (12 ml) is added a second solution of 2-(5-bromo-2-difluoromethoxyphenyl)-4,4,6,6-tetramethyl-1,5-dioxaspiro[2.4]heptan-7-one (7.22 g, 18.00 mmol) in 1,2-dichloroethane (12 ml) dropwise over 5 minutes. This biphasic mixture is stirred vigorously for 2 hours at 0° C., then allowed to stand at room temperature overnight. The reaction mixture is poured into ice-water, rinsing with a small amount of additional 1,2-dichloroethane/water, then concentrated under vacuum to remove all organic solvents. The crude product is next extracted into ethyl acetate (×3), than all organics are combined, washed with brine, and dried over magnesium sulfate. The suspension is filtered and the filtrate is concentrated in vacuo then purified by flash column chromatography (10% to 25% ethyl acetate in hexane as eluant) to give an oil which is triturated with hexanes to afford 4-(5-bromo-2-difluoromethoxyphenyl)-2,2,6,6-tetramethylpyran-3,5-dione (2.08 g) as a white solid.

Workup

  1. waitto stand at room temperature overnight
  2. washrinsing with a small amount of additional 1,2-dichloroethane/water
  3. concentrationconcentrated under vacuum
  4. customto remove all organic solvents
  5. extractionThe crude product is next extracted into ethyl acetate (×3)
  6. washwashed with brine
  7. dry with materialdried over magnesium sulfate
  8. filtrationThe suspension is filtered
  9. concentrationthe filtrate is concentrated in vacuo
  10. customthen purified by flash column chromatography (10% to 25% ethyl acetate in hexane as eluant)
  11. customto give an oil which
  12. customis triturated with hexanes

Sources & evidence

ORD record
ord-928a1944f2ff414cab65a1c727ab3f9d
Source dataset
uspto-grants-2014_03
Patent number
US08680299B2

Reaction notes

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