Sulfuric Acid → 2-Bromo-7-methoxy-9H-xanthen-9-one

HRID 1472300Notes

Reaction equation

HRID 1472300 reaction equation
S(=O)(=O)(O)O.[Br:6][C:7]1[CH:24]=[CH:23][C:10]([O:11][C:12]2[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[CH:17][C:13]=2[C:14]([OH:16])=O)=[CH:9][CH:8]=1>>[Br:6][C:7]1[CH:8]=[CH:9][C:10]2[O:11][C:12]3[C:13](=[CH:17][C:18]([O:21][CH3:22])=[CH:19][CH:20]=3)[C:14](=[O:16])[C:23]=2[CH:24]=1

Participants

3

Reactant 2

HCID 1118Sulfuric AcidHCID 574756322-(4-Bromophenoxy)-5-methoxybenzoic acid

Product 1

HCID 574756332-Bromo-7-methoxy-9H-xanthen-9-oneYield 259.8%

Conditions

Temperature
60 °C

Procedure

A RBF equipped with a reflux condenser was charged with 2-bromo-5-methoxy benzoic acid (430 g, 1.8614 mol), 4-bromo phenol (322 g, 1.8614 mol), potassium carbonate (514.5 g, 3.7 228 mol) and CuOTf-toluene complex (24.08 g, 0.04653 mol). EtOAc (9.0 ml 0.09679 mol, 0.052) and toluene (1.3 L) were carefully added portion wise. After stirring at RT for 10 min, the mixture was heated to 50° C. for 30 min and then to 110° C. for 20 hrs. The reaction mixture was cooled to RT and diluted with water and acidified with 2N HCl. The reaction mixture was extracted with EtOAc (3.0×2 L) and filtered through a pad of celite. The combined extracts were dried over sodium sulfate and concentrated to provide 590 g of a brown solid that was carried on without further purification. Step 2: Sulfuric acid (1.6 L) was added to 2-(4-bromophenoxy)-5-methoxybenzoic acid (530 g, 1.6401mol) at RT. The resulting dark mixture was heated to 60° C. for 1 hour. The brown solution was cooled to RT and poured onto ice while stirring. The resulting tan precipitate was collected by filtration, washed sequentially with water (2 L), 1N NaOH (2.0 L) and ethanol (800 mL). The derived solid was suspended in 2 L of acetone and stiffed vigorously for 1 hour. The mixture was filtered and dried under a vacuum to afford 1.3 kg of 2-bromo-7-methoxy-9H-xanthen-9-one as a white solid.

Workup

  1. customthat was carried on without further purification
  2. temperatureThe brown solution was cooled to RT
  3. additionpoured onto ice
  4. filtrationThe resulting tan precipitate was collected by filtration
  5. washwashed sequentially with water (2 L), 1N NaOH (2.0 L) and ethanol (800 mL)
  6. filtrationThe mixture was filtered
  7. customdried under a vacuum

Sources & evidence

ORD record
ord-a4efff3de6694a188847a3c4bdc3e93a
Source dataset
uspto-grants-2015_04
Patent number
US09012446B2

Reaction notes

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