Carbon Dioxide → 6,7,8,9-tetrahydro-9,9-dimethyl-5H-benzocycloheptene-2-carboxylic acid

HRID 653811Notes

Reaction equation

HRID 653811 reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]2[CH2:11][CH2:10][CH2:9][CH2:8][C:7]([CH3:13])([CH3:12])[C:6]=2[CH:14]=1.[C:15](=[O:17])=[O:16].Cl>O1CCCC1>[CH3:12][C:7]1([CH3:13])[C:6]2[CH:14]=[C:2]([C:15]([OH:17])=[O:16])[CH:3]=[CH:4][C:5]=2[CH2:11][CH2:10][CH2:9][CH2:8]1

Participants

5

Reactant 3

HCID 280Carbon DioxideHCID 313Hydrochloric AcidHCID 230025142-bromo-6,7,8,9-tetrahydro-9,9-dimethyl-5H-benzocycloheptene

Product 1

HCID 189899956,7,8,9-tetrahydro-9,9-dimethyl-5H-benzocycloheptene-2-carboxylic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

The Grignard compound was prepared under an argon atmosphere from 4.00 g of 2-bromo-6,7,8,9-tetrahydro-9,9--dimethyl-5H-benzocycloheptene, as described in EP-A2-0315071, and 456 mg of Mg shavings in 20 ml of absolute tetrahydrofuran. After carrying out the metallation a vigorous CO2 stream was introduced at -10° C. The mixture was hydrolyzed with dil. HCl, extracted with ether and washed with a small amount of water. The acid was then purified by extraction in lN NaOH, acidification to pH 1 (HCl) and re-extraction in ether. After washing with water, drying over Na2SO4 and evaporating there were obtained 2.64 g of 6,7,8,9--tetrahydro-9,9-dimethyl-5H-benzocycloheptene-2-carboxylic acid as colorless crystals of melting point 155° C.-156° C.

Workup

  1. additionwas introduced at -10° C
  2. extractionextracted with ether
  3. washwashed with a small amount of water
  4. customThe acid was then purified by extraction in lN NaOH
  5. extractionacidification to pH 1 (HCl) and re-extraction in ether
  6. washAfter washing with water
  7. dry with materialdrying over Na2SO4
  8. customevaporating there

Sources & evidence

ORD record
ord-6ef22d051abe49a680e8ec26ffb7515c
Source dataset
uspto-grants-1992_07
Patent number
US05128470

Reaction notes

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