Potassium Hydroxide → 10,11-dihydro-5H-dibenzo[a,d]cycloheptene-5-malonic acid

HRID 2308836Notes

Reaction equation

HRID 2308836 reaction equation
[CH:1]1[C:11]2[CH2:10][CH2:9][C:8]3[CH:12]=[CH:13][CH:14]=[CH:15][C:7]=3[CH:6]([CH:16]([C:22]([O:24]CC)=[O:23])[C:17]([O:19]CC)=[O:18])[C:5]=2[CH:4]=[CH:3][CH:2]=1.[OH-].[K+]>C(O)C.O>[CH:1]1[C:11]2[CH2:10][CH2:9][C:8]3[CH:12]=[CH:13][CH:14]=[CH:15][C:7]=3[CH:6]([CH:16]([C:22]([OH:24])=[O:23])[C:17]([OH:19])=[O:18])[C:5]=2[CH:4]=[CH:3][CH:2]=1

Participants

5

Reactant 2

HCID 14797Potassium HydroxideHCID 20187928Diethyl 10,11-dihydro-5H-dibenzo[a,d]cycloheptene-5-malonate

Product 1

HCID 2018793310,11-dihydro-5H-dibenzo[a,d]cycloheptene-5-malonic acid

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

A solution of 305 g of crude diethyl 10,11-dihydro-5H-dibenzo[a,d]cycloheptene-5-malonate and 138 g of potassium hydroxide in 1.5 l of ethanol and 400 ml of water is heated to boiling under reflux for 1.5 hours while stirring and subsequently evaporated in vacuo. The residue obtained is partitioned between 1 l of ether and 1 l of ice-water. The aqueous, alkaline phase is extracted further with 500 ml of ether, made acid with about 220 ml of concentrated hydrochloric acid while cooling with ice and extracted with 2 l of ether. The ethereal phase is washed three times with 500 ml of water each time and the aqueous washings are back-extracted with 1 l of ether. The combined ether extracts are washed for an additional three to four times with saturated sodium chloride solution, dried over magnesium sulfate and concentrated to a volume of about 400 ml. After dilution with 300 ml of petroleum ether, the clear solution obtained is cooled in an ice-bath and left to stand at 4° overnight. The crystallized-out material is removed by filtration under suction while back-washing with petroleum ether and dried at 50° in a vacuum drying oven. There is obtained 10,11-dihydro-5H-dibenzo[a,d]cycloheptene-5-malonic acid of melting point 183° (with decarboxylation).

Workup

  1. temperatureunder reflux for 1.5 hours
  2. customsubsequently evaporated in vacuo
  3. customThe residue obtained
  4. customis partitioned between 1 l of ether and 1 l of ice-water
  5. extractionThe aqueous, alkaline phase is extracted further with 500 ml of ether
  6. temperaturewhile cooling with ice
  7. extractionextracted with 2 l of ether
  8. washThe ethereal phase is washed three times with 500 ml of water each time
  9. extractionthe aqueous washings are back-extracted with 1 l of ether
  10. washThe combined ether extracts are washed for an additional three to four times with saturated sodium chloride solution
  11. dry with materialdried over magnesium sulfate
  12. concentrationconcentrated to a volume of about 400 ml
  13. customAfter dilution with 300 ml of petroleum ether, the clear solution obtained
  14. temperatureis cooled in an ice-bath
  15. waitleft
  16. customThe crystallized-out material is removed by filtration under suction
  17. washwhile back-washing with petroleum ether
  18. customdried at 50° in a vacuum
  19. customdrying oven

Sources & evidence

ORD record
ord-3e65350942984811b15b99a481bf1238
Source dataset
uspto-grants-1987_09
Patent number
US04691040

Reaction notes

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