Pyridine → Dibenzo[a,c]cycloheptene-4-carbonitrile

HRID 544677Notes

Reaction equation

HRID 544677 reaction equation
[CH2:1]1[C:6]2=[C:7]3[CH:15]=[CH:14][CH:13]=[CH:12][C:8]3=[CH:9][CH:10]=[CH:11][C:5]2=[CH:4][CH:3]=[CH:2]1.[N:16]1C=CC=C[CH:17]=1>C(Cl)Cl>[CH2:15]1[C:7]2=[C:6]3[CH:1]=[CH:2][CH:3]=[CH:4][C:5]3=[CH:11][CH:10]=[CH:9][C:8]2=[C:12]([C:17]#[N:16])[CH:13]=[CH:14]1

Participants

4

Reactant 2

HCID 1049PyridineHCID 19771677Dibenzo[a,c]cycloheptene

Product 1

HCID 20458457Dibenzo[a,c]cycloheptene-4-carbonitrile

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

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). Under a dry nitrogen atmosphere a mixture of 4-chloro-6,7-dihydro-5e,uns/H/ -dibenzo[a,c]cycloheptene (1.6 grams, 0.007 mole), cuprous cyanide (0.95 gram, 0.011 mole), and pyridine (0.8 gram, 0.01 mole) was stirred and heated at 195° for approximately 16 hours. The mixture was cooled, dissolved in methylene chloride (150 ml), and the resultant solution was washed with three 70 ml portions of concentrated ammonium hydroxide. The organic phase was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated under reduced pressure to give a brown solid. Recrystallization from n-hexane gave 6,7-dihydro-5e,uns/H/ -dibenzo[a,c]cycloheptene-4-carbonitrile (mp 109°-111°).

Workup

  1. temperatureheated at 195° for approximately 16 hours
  2. temperatureThe mixture was cooled
  3. washthe resultant solution was washed with three 70 ml portions of concentrated ammonium hydroxide
  4. dry with materialThe organic phase was dried over anhydrous magnesium sulfate
  5. filtrationfiltered
  6. customThe filtrate was evaporated under reduced pressure
  7. customto give a brown solid
  8. customRecrystallization from n-hexane

Sources & evidence

ORD record
ord-d763303440fc4be8a633455ff080835f
Source dataset
uspto-grants-1984_05
Patent number
US04451484

Reaction notes

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