HCID 86663660, compound → HCID 66823480, compound

HRID 1193214Notes

Reaction equation

HRID 1193214 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]([CH2:19][CH3:20])=[C:6]([CH:8]2[C:10]3([C:14](=[O:15])[C:13]([CH3:17])([CH3:16])[O:12][CH:11]3[CH3:18])[O:9]2)[CH:7]=1>ClCCCl>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([CH2:19][CH3:20])=[C:6]([CH:8]2[C:10](=[O:9])[CH:11]([CH3:18])[O:12][C:13]([CH3:17])([CH3:16])[C:14]2=[O:15])[CH:7]=1

Participants

3

Reactant 1

HCID 86663660HCID 86663660, compound

Product 1

HCID 66823480HCID 66823480, compoundYield 35.3%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Conditions

Temperature
0 °C

Procedure

To ice-cold concentrated sulphuric acid (50 ml) is added a solution of crude 2-(5-bromo-2-ethylphenyl)-4,6,6-trimethyl-1,5-dioxaspiro[2.4]heptan-7-one (40 g) in 1,2-dichloroethane (50 ml) over 20 minutes. After further stirring at 0° C. for 1 hour the reaction mixture is carefully poured into ice (500 g), and the two phases separated. The aqueous phase is further extracted with dichloromethane (2×100 ml), then all organic fractions are combined, washed with water, and concentrated under reduced pressure. The crude product is re-dissolved in ethyl acetate (500 ml), extracted into 0.5M aqueous potassium carbonate, and washed with additional ethyl acetate (×2). The aqueous phase is then carefully acidified with concentrated hydrochloric acid, and the product extracted with ethyl acetate (3×150 ml). Organic fractions are combined, washed with brine then dried over magnesium sulfate, filtered, and the filtrate concentrated in vacuo. The crude product is further purified by flash column chromatography to afford 4-(5-bromo-2-ethylphenyl)-2,2,6-trimethylpyran-3,5-dione (14.10 g) as a white foam.

Workup

  1. customthe two phases separated
  2. extractionThe aqueous phase is further extracted with dichloromethane (2×100 ml)
  3. washwashed with water
  4. concentrationconcentrated under reduced pressure
  5. dissolutionThe crude product is re-dissolved in ethyl acetate (500 ml)
  6. extractionextracted into 0.5M aqueous potassium carbonate
  7. washwashed with additional ethyl acetate (×2)
  8. extractionthe product extracted with ethyl acetate (3×150 ml)
  9. washwashed with brine
  10. dry with materialthen dried over magnesium sulfate
  11. filtrationfiltered
  12. concentrationthe filtrate concentrated in vacuo
  13. customThe crude product is further purified by flash column chromatography

Sources & evidence

ORD record
ord-35cd831e16024cdcbc6dc344d723e942
Source dataset
uspto-grants-2014_03
Patent number
US08680299B2

Reaction notes

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