Sulfuric Acid → HCID 49787146, compound

HRID 879068Notes

Reaction equation

HRID 879068 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:13]=[CH:12][C:11]([Cl:14])=[CH:10][CH:9]=2)=[CH:4][C:3]=1[CH:15]1[C:17]2([C:21](=[O:22])[C:20]([CH3:24])([CH3:23])[O:19][C:18]2([CH3:26])[CH3:25])[O:16]1.S(=O)(=O)(O)O>ClCCl>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:9]=[CH:10][C:11]([Cl:14])=[CH:12][CH:13]=2)=[CH:4][C:3]=1[CH:15]1[C:21](=[O:22])[C:20]([CH3:23])([CH3:24])[O:19][C:18]([CH3:26])([CH3:25])[C:17]1=[O:16]

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 86663665HCID 86663665, compound

Product 1

HCID 49787146HCID 49787146, compoundYield 85.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
7.5 °C

Procedure

To an ice-cold solution of 2-(4-bromo-4′-chlorobiphenyl-3-yl)-4,4,6,6-tetramethyl-1,5-dioxaspiro[2.4]heptan-7-one (3.00 g, 6.90 mmol) in dichloromethane (3.5 ml) is added concentrated sulphuric acid (6.5 ml) at such a rate as maintain an internal temperature below 5° C. After the addition is completed the reaction mixture is stirred for a further 20 minutes, after which distilled water (25 ml) is added dropwise at 0° C. The reaction mixture is maintained at 5-10° C. for 5 minutes, then concentrated in vacuo to remove organic solvents. The aqueous phase is filtered and the resulting solid triturated with hexane to afford 4-(4-bromo-4′-chlorobiphenyl-3-yl)-2,2,6,6-tetramethylpyran-3,5-dione (2.56 g, 85%).

Workup

  1. temperatureas maintain an internal temperature below 5° C
  2. additionAfter the addition
  3. distillationafter which distilled water (25 ml)
  4. additionis added dropwise at 0° C
  5. concentrationconcentrated in vacuo
  6. customto remove organic solvents
  7. filtrationThe aqueous phase is filtered
  8. customthe resulting solid triturated with hexane

Sources & evidence

ORD record
ord-0da034f233ee41fc9f8cc0b36ada14b1
Source dataset
uspto-grants-2015_03
Patent number
US08987476B2

Reaction notes

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