Potassium Hydroxide → 4-chloro-6,7-dihydro-5H-dibenzo[a,c]cycloheptene

HRID 1388820Notes

Reaction equation

HRID 1388820 reaction equation
[Cl:1][C:2]1[C:12]2[CH2:11][CH2:10][C:9](=O)[C:8]3[CH:14]=[CH:15][CH:16]=[CH:17][C:7]=3[C:6]=2[CH:5]=[CH:4][CH:3]=1.O.NN.[OH-].[K+]>C(O)CO>[Cl:1][C:2]1[C:12]2[CH2:11][CH2:10][CH2:9][C:8]3[CH:14]=[CH:15][CH:16]=[CH:17][C:7]=3[C:6]=2[CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 14797Potassium HydroxideHCID 24654Hydrazine hydrate (1:1)HCID 204033458-chloro-6,7-dihydro-5H-dibenzo[a,c]cycloheptene-5-one

Product 1

HCID 132813394-chloro-6,7-dihydro-5H-dibenzo[a,c]cycloheptene

Reagents, catalysts & solvents 1

HCID 174Ethylene GlycolSolvent

Procedure

Under a dry nitrogen atmosphere a stirred mixture of 8-chloro-6,7-dihydro-5H-dibenzo[a,c]cycloheptene-5-one (2.6 grams, 0.011 mole), 85% hydrazine hydrate (5 ml, 0.1 mole), potassium hydroxide (4 grams, 0.071 mole) and ethylene glycol (30 ml) was heated at reflux for 1.5 hours. Sufficient volatiles were removed by distillation to increase the pot temperature to 200° while maintaining reflux. The two-phase reaction mixture was refluxed at that temperature for three hours. The mixture was cooled, poured into ice water, and the resultant mixture extracted with diethyl ether. The extract was washed with water, dried over anhydrous magnesium sulfate, and filtered. The filtrate was evaporated under reduced pressure to give a yellow oil. The oil was purified by distillation to give 4-chloro-6,7-dihydro-5H-dibenzo[a,c]cycloheptene (bp 119°-126°/0.15 mm).

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 1.5 hours
  3. customSufficient volatiles were removed by distillation
  4. temperatureto increase the pot temperature to 200°
  5. temperaturewhile maintaining
  6. temperaturereflux
  7. customThe two-phase reaction mixture
  8. temperaturewas refluxed at that temperature for three hours
  9. temperatureThe mixture was cooled
  10. extractionthe resultant mixture extracted with diethyl ether
  11. washThe extract was washed with water
  12. dry with materialdried over anhydrous magnesium sulfate
  13. filtrationfiltered
  14. customThe filtrate was evaporated under reduced pressure
  15. customto give a yellow oil
  16. distillationThe oil was purified by distillation

Sources & evidence

ORD record
ord-ec4547f69a8c4e5abb68070db19eee70
Source dataset
uspto-grants-1984_02
Patent number
US04433182

Reaction notes

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