Potassium Carbonate → HCID 13723675, compound

HRID 1448965Notes

Reaction equation

HRID 1448965 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]([OH:10])[C:5](=[CH:7][C:8]=1[CH3:9])[OH:6].C(=O)([O-])[O-].[K+].[K+].Br[C:18](Br)([CH3:24])[C:19]([O:21][CH2:22][CH3:23])=[O:20]>CC(C)=O>[CH3:1][C:2]1[C:8]([CH3:9])=[CH:7][C:5]2[O:6][CH:18]([C:19]([O:21][CH2:22][CH3:23])=[O:20])[CH2:24][O:10][C:4]=2[CH:3]=1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 10901348Propanoic acid, 2,2-dibromo-, ethyl esterHCID 127302874,5-Dimethylbenzene-1,2-diol

Product 1

HCID 13723675HCID 13723675, compoundYield 319.7%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

A stirred solution of 4,5-dimethylcatechol (7.0 g.) in dry acetone (45 ml.) was heated under reflux, then potassium carbonate (5 g.) was added followed by the dropwise addition of ethyl dibromopropionate (3.5 g.). The addition procedure was repeated a further three times over 11/4 hours then the reaction was stirred under reflux for a further 33/4 hours. After cooling, the mixture was filtered, the solids washed well with acetone then the combined filtrate concentrated in vacuo. Water (35 ml.) was added, the resulting solid collected, washed with petrol then taken up in ether. The ethereal solution was washed with water, dried (Na2SO4) and evaporated in vacuo to give ethyl 6,7-dimethyl-1,4-benzodioxan-2-carboxylate (10.17 g.), m.p. 70°-71° C.

Workup

  1. temperatureunder reflux
  2. additionThe addition procedure
  3. custom4 hours
  4. temperatureunder reflux for a further 33/4 hours
  5. temperatureAfter cooling
  6. filtrationthe mixture was filtered
  7. washthe solids washed well with acetone
  8. concentrationthe combined filtrate concentrated in vacuo
  9. additionWater (35 ml.) was added
  10. customthe resulting solid collected
  11. washwashed with petrol
  12. washThe ethereal solution was washed with water
  13. dry with materialdried (Na2SO4)
  14. customevaporated in vacuo

Sources & evidence

ORD record
ord-dd7618234cba4d3ea4d9b913834d861f
Source dataset
uspto-grants-1980_02
Patent number
US04188390

Reaction notes

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