2,3-Dihydroxybenzoic Acid → 2,3-Dihydro-1,4-benzodioxin-5-carboxylic acid

HRID 581062Notes

Reaction equation

HRID 581062 reaction equation
[OH:1][C:2]1[C:10]([OH:11])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].C(=O)([O-])[O-].[K+].[K+].Br[CH2:19][CH2:20]Br>CN(C)C=O.O>[C:4]([C:3]1[C:2]2[O:1][CH2:20][CH2:19][O:11][C:10]=2[CH:9]=[CH:8][CH:7]=1)([OH:6])=[O:5]

Participants

6

Reactant 3

HCID 192,3-Dihydroxybenzoic AcidHCID 78391,2-DibromoethaneHCID 11430Potassium Carbonate

Product 1

HCID 781842,3-Dihydro-1,4-benzodioxin-5-carboxylic acid

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Conditions

Temperature
65 °C

Procedure

A mixture of 10.8 g (70 mmol) of 2,3-dihydroxybenzoic acid, 38.6 g (280 mmol) of dry potassium carbonate and 24 ml (278 mmol) of 1,2-dibromoethane in 40 ml of N,N-dimethylformamide is heated at 65° C. for 24 hours under an inert atmosphere. After cooling, the reaction mixture is diluted with water and then extracted with ether. The aqueous phase is then acidified with a 3N hydrochloric acid solution and subsequently extracted with dichloromethane. After removal of the solvent by evaporation in vacuo, the residue obtained is recrystallised from toluene to yield the title acid in the form of a white solid.

Workup

  1. temperatureAfter cooling
  2. extractionextracted with ether
  3. extractionsubsequently extracted with dichloromethane
  4. customAfter removal of the solvent
  5. customby evaporation in vacuo
  6. customthe residue obtained
  7. customis recrystallised from toluene

Sources & evidence

ORD record
ord-21253bf35f474d2d90338f4eb2cf3cb0
Source dataset
uspto-grants-1999_07
Patent number
US05919814

Reaction notes

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