Benzene → HCID 21439127, compound

HRID 1283674Notes

Reaction equation

HRID 1283674 reaction equation
[O:1]=[C:2]1[C:8]2[CH:9]=[CH:10][C:11]([CH:13](C)C(O)=O)=[CH:12][C:7]=2[CH:6]=[CH:5][C:4]2[CH:18]=[CH:19][CH:20]=[CH:21][C:3]1=2.C1C=CC=CC=1.FC(F)(F)C([O:32][C:33](=[O:38])[C:34](F)(F)F)=O.C1(C(O)C)C=CC=CC=1>CCOCC.O>[O:1]=[C:2]1[C:8]2[CH:9]=[CH:10][C:11]([CH2:13][CH2:34][C:33]([OH:32])=[O:38])=[CH:12][C:7]=2[CH:6]=[CH:5][C:4]2[CH:18]=[CH:19][CH:20]=[CH:21][C:3]1=2

Participants

7

Reactant 4

HCID 241BenzeneHCID 74091-PhenylethanolHCID 9845Trifluoroacetic anhydrideHCID 1739105H-Dibenzo(a,d)cycloheptene-2-acetic acid, alpha-methyl-5-oxo-

Product 1

HCID 21439127HCID 21439127, compound

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 3283Diethyl EtherSolvent

Procedure

2.78 G. of 2-(5-oxo-5H-dibenzo[a,d]cyclohepten-2-yl)propionic acid is stirred in a mixture of 20 ml. of benzene and 5 ml. of trifluoroacetic anhydride for 15 minutes. The mixture is evaporated to dryness and redissolved in 20 ml. of dry benzene. A mixture of 1.0 g. of pyridine and 2.44 g. (2 moles) of (+) α-phenylethanol is added. The mixture is left for 30 minutes and then water and ether is added. The organic layer is washed with dilute hydrochloric acid and water, then dried and evaporated. The residue is chromatographed on 100 g. silica gel, eluting with hexane:ether (4:1) to afford a 1:1 mixture of diastereomeric esters. Repeated crystallization of this mixture from ether-hexane yields the less soluble isomers. The purity of samples from successive recrystallizations is monitored by gas-liquid chromatography using a 1 meter × 2 mm. column packed with Chromosorb W (Regis Chemical Co., Chicago, Ill.) impregnated with 3% w/w OV101 polymeric material (Applied Sciences Laboratory, Inc., State College, Penn.) as stationary phase, and helium as the carrier gas at 220°C. The less soluble isomer is decomposed by stirring in a mixture of 5 ml. of benzene and 5 ml. of trifluoroacetic acid for 30 minutes. Water and ether are added and the ethereal layer washed with water, and then with dilute aqueous sodium carbonate. The aqueous layer is acidified with dilute hydrochloric acid and then extracted with ether. The ethereal layer is washed, dried and evaporated to give d 3-(5-oxo-5H-dibenzo[a,d]cyclohepten-2-yl)propionic acid. 1 2-(5-Oxo-5H-dibenzo[a,d]cyclohepten-2yl)propionic acid [m.p. 105°-107°C; [α]D -47.4° (chloroform)] can be obtained in similar manner using (-) α-phenylethanol.

Workup

  1. customThe mixture is evaporated to dryness
  2. dissolutionredissolved in 20 ml
  3. additionA mixture of 1.0 g
  4. washThe organic layer is washed with dilute hydrochloric acid and water
  5. customdried
  6. customevaporated
  7. customThe residue is chromatographed on 100 g
  8. washsilica gel, eluting with hexane:ether (4:1)
  9. customto afford
  10. customcrystallization of this mixture from ether-hexane
  11. customyields the less soluble isomers
  12. customThe purity of samples from successive recrystallizations
  13. customimpregnated with 3% w/w OV101 polymeric material (Applied Sciences Laboratory, Inc., State College, Penn.) as stationary phase, and helium as the carrier gas at 220°C
  14. waitof trifluoroacetic acid for 30 minutes
  15. additionWater and ether are added
  16. washthe ethereal layer washed with water
  17. extractionextracted with ether
  18. washThe ethereal layer is washed
  19. customdried
  20. customevaporated

Sources & evidence

ORD record
ord-41c4737d153a461f88fbafde023b9c16
Source dataset
uspto-grants-1976_08
Patent number
US03975540

Reaction notes

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