Sulfuric Acid → 4-(5-Bromo-2-trifluoromethoxyphenyl)-2,2,6,6-tetramethylpyran-3,5-dione

HRID 879064Notes

Reaction equation

HRID 879064 reaction equation
S(=O)(=O)(O)O.[Br:6][C:7]1[CH:8]=[CH:9][C:10]([O:25][C:26]([F:29])([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][C:26]([F:28])([F:29])[F:27])=[C:11]([CH:13]2[C:19](=[O:20])[C:18]([CH3:21])([CH3:22])[O:17][C:16]([CH3:24])([CH3:23])[C:15]2=[O:14])[CH:12]=1

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 580612462-(5-Bromo-2-trifluoromethoxyphenyl)-4,4,6,6-tetramethyl-1,5-dioxaspiro[2.4]heptan-7-one

Product 1

HCID 666804614-(5-Bromo-2-trifluoromethoxyphenyl)-2,2,6,6-tetramethylpyran-3,5-dioneYield 68%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Conditions

Temperature
0 °C

Procedure

To an ice-cold solution of concentrated sulphuric acid (10 ml) is added a second solution of 2-(5-bromo-2-trifluoromethoxyphenyl)-4,4,6,6-tetramethyl-1,5-dioxaspiro[2.4]heptan-7-one (6.34 g, 15.00 mmol) in 1,2-dichloroethane (10 ml) dropwise over 5 minutes. This biphasic mixture is stirred vigorously for 2 hours at 0° C., then poured into ice-water, rinsing with a small amount of additional 1,2-dichloroethane/water. This mixture is then concentrated under vacuum to remove all organic solvents, until a free-flowing solid was produced. The solid is filtered, washed with water then isohexane, followed by drying under vacuum overnight. The solid is next redissolved in ethyl acetate, dried over magnesium sulfate, filtered and the filtrate concentrated in vacuo to afford 4-(5-bromo-2-trifluoromethoxyphenyl)-2,2,6,6-tetramethylpyran-3,5-dione (4.17 g, 68%).

Workup

  1. washrinsing with a small amount of additional 1,2-dichloroethane/water
  2. concentrationThis mixture is then concentrated under vacuum
  3. customto remove all organic solvents
  4. customuntil a free-flowing solid was produced
  5. filtrationThe solid is filtered
  6. washwashed with water
  7. customby drying under vacuum overnight
  8. dissolutionThe solid is next redissolved in ethyl acetate
  9. dry with materialdried over magnesium sulfate
  10. filtrationfiltered
  11. concentrationthe filtrate concentrated in vacuo

Sources & evidence

ORD record
ord-3d0954e846b447fc93fe9b5e8941f13d
Source dataset
uspto-grants-2015_03
Patent number
US08987476B2

Reaction notes

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