Hydrochloric Acid → 1-Ethyl 2-[(4-fluorophenyl)phenylmethylene]butanedioate

HRID 485404Notes

Reaction equation

HRID 485404 reaction equation
[F:1][C:2]1[CH:15]=[CH:14][C:5]([C:6]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)=O)=[CH:4][CH:3]=1.[C:16]([O:25]CC)(=[O:24])[CH2:17][CH2:18][C:19]([O:21][CH2:22][CH3:23])=[O:20].CC(C)([O-])C.[K+].Cl>C(O)(C)(C)C>[CH2:22]([O:21][C:19]([C:18](=[C:6]([C:5]1[CH:14]=[CH:15][C:2]([F:1])=[CH:3][CH:4]=1)[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[CH2:17][C:16]([OH:25])=[O:24])=[O:20])[CH3:23]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 31249Diethyl SuccinateHCID 676634-FluorobenzophenoneHCID 23665647Potassium tert-butoxide

Product 1

HCID 544389311-Ethyl 2-[(4-fluorophenyl)phenylmethylene]butanedioateYield 70%

Reagents, catalysts & solvents 1

HCID 6386tert-ButanolSolvent

Procedure

A solution of commercially available 4-fluorobenzophenone (42 g., 0.21 mole), diethyl succinate (43.6 g., 0.25 mole) and potassium t-butoxide (23.7 g., 0.21 mole) in t-butanol (250 ml.) was stirred at reflux for 6 hours and then stirred at room temperature for an additional 16 hours. The reaction mixture was then acidified with 6N hydrochloric acid (200 ml.), evaporated under vacuum to remove the t-butanol and extracted with ether (2×250 ml.). The combined ether extract was extracted with 10% aqueous ammonium hydroxide (2×350 ml.). The combined aqueous extract was washed with ether (2×200 ml.), re-acidified with 6N hydrochloric acid and extracted again with ether (2×400 ml.). The combined ether extract was dried (MgSO4), filtered and evaporated under vacuum to an oil, which was crystallized by dissolution in hexane (100 ml.) followed by scratching the flask to initiate crystallization (48 g., 70% yield, m.p. 98°-99° C., elemental analysis calculated: 69.50% C; 5.22% H; 5.78% F; found: 69.34% C; 5.36% H; 6.09% F).

Workup

  1. temperatureat reflux for 6 hours
  2. customevaporated under vacuum
  3. customto remove the t-butanol
  4. extractionextracted with ether (2×250 ml.)
  5. extractionThe combined ether extract
  6. extractionwas extracted with 10% aqueous ammonium hydroxide (2×350 ml.)
  7. extractionThe combined aqueous extract
  8. washwas washed with ether (2×200 ml.), re-acidified with 6N hydrochloric acid
  9. extractionextracted again with ether (2×400 ml.)
  10. extractionThe combined ether extract
  11. dry with materialwas dried (MgSO4)
  12. filtrationfiltered
  13. customevaporated under vacuum to an oil, which
  14. customwas crystallized by dissolution in hexane (100 ml.)
  15. customcrystallization (48 g., 70% yield, m.p. 98°-99° C., elemental analysis calculated: 69.50% C; 5.22% H; 5.78% F; found: 69.34% C; 5.36% H; 6.09% F)

Sources & evidence

ORD record
ord-8e88354d573348939d85ce9d945a4149
Source dataset
uspto-grants-1985_08
Patent number
US04536518

Reaction notes

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