Cornforth reagent → 4-Benzoyl-5-hydroxybenzocyclobutene-1-carboxylic acid

HRID 1248350Notes

Reaction equation

HRID 1248350 reaction equation
[OH:1][CH:2]([C:9]1[C:19]([OH:20])=[CH:18][C:12]2[C:13]([C:15]([OH:17])=[O:16])=[CH:14][C:11]=2[CH:10]=1)[C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1.[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>ClCCl>[C:2]([C:9]1[C:19]([OH:20])=[CH:18][C:12]2[C:13]([C:15]([OH:17])=[O:16])=[CH:14][C:11]=2[CH:10]=1)(=[O:1])[C:3]1[CH:4]=[CH:5][CH:6]=[CH:7][CH:8]=1

Participants

4

Reactant 2

HCID 2724130Cornforth reagentHCID 202794214-(alpha-Hydroxybenzyl)-5-hydroxybenzocyclobutene-1-carboxylic acid

Product 1

HCID 202794244-Benzoyl-5-hydroxybenzocyclobutene-1-carboxylic acid

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

3.0 g of 4-(α-hydroxybenzyl)-5-hydroxybenzocyclobutene-1-carboxylic acid are dissolved in 30 ml of dichloromethane and over a period of 10 minutes, while stirring, 30 g of pyridinium dichromate in 100 ml of dichloromethane are added dropwise thereto. Stirring is then carried out for 7 hours at room temperature, and the mixture is decanted off from the black residue, filtered over silica gel, concentrated to dryness by evaporation and crystallised from ether/hexane. 4-benzoyl-5-hydroxybenzocyclobutene-1-carboxylic acid is obtained having a melting point of 167°-169°.

Workup

  1. stirringStirring
  2. customthe mixture is decanted off from the black residue
  3. filtrationfiltered over silica gel
  4. concentrationconcentrated to dryness by evaporation
  5. customcrystallised from ether/hexane

Sources & evidence

ORD record
ord-29ded61d3dfa4b17bb0dc28dbc87a46d
Source dataset
uspto-grants-1985_06
Patent number
US04523030

Reaction notes

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