Cyclohexane → 3-Acetyl-3a,7a-dihydro-7a-(phenylethynyl)benzofuran-2,5(3H,4H)-dione

HRID 2291901Notes

Reaction equation

HRID 2291901 reaction equation
[OH:1][C:2]1([C:9]#[C:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[CH:7]=[CH:6][C:5](=[O:8])[CH:4]=[CH:3]1.[Li+].CC([N-]C(C)C)C.C1CCCCC1.[CH2:31]=[C:32]1[O:36][C:34](=[O:35])[CH2:33]1>C1COCC1.CN(C=O)C>[C:32]([CH:33]1[CH:3]2[CH2:4][C:5](=[O:8])[CH:6]=[CH:7][C:2]2([C:9]#[C:10][C:11]2[CH:12]=[CH:13][CH:14]=[CH:15][CH:16]=2)[O:1][C:34]1=[O:35])(=[O:36])[CH3:31]

Participants

7

Reactant 4

HCID 8078CyclohexaneHCID 12661Diketene2×HCID 2724682Lithium diisopropylamide2×HCID 110091862,5-Cyclohexadien-1-one, 4-hydroxy-4-(phenylethynyl)-

Product 1

HCID 143028923-Acetyl-3a,7a-dihydro-7a-(phenylethynyl)benzofuran-2,5(3H,4H)-dioneYield 53%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-30 °C

Procedure

4-Hydroxy-4-(phenylethynyl)-2,5-cyclohexadien-1-one, the product of Example 2A, (10.5 g, 0.05 mole) was dissolved in dry THF (100 mL). The reaction was cooled to -30° C. and treated with 1.96M LDA in cyclohexane (25.5 mL, 0.05 mole). During the addition of the LDA solution, a beige-colored slurry formed. The reaction was cooled to -78° C. and stirred at that temperature for 40 min. Dry DMF (10 mL) was added. The reaction immediately became homogeneous. Diketene (6.3 mL, 0.08 mole) was added rapidly and the reaction was stirred for 20 min before an additional portion of diketene (4.0 mL 0.05 mole) was added. The stirred reaction was allowed to warm slowly to 0° C., then quenched into ice (300 g) and concentrated hydrochloric acid (45 mL). The resulting mixture was extracted with CH2Cl2. The combined extracts were washed with water, dried over anhydrous sodium sulfate overnight, filtered and concentrated. The resulting solution was concentrated in vacuo. The residue was treated with Et2O (300 mL) and cooled to 0° C. for 1 hr. The resulting solid was isolated by filtration and washed with Et2O to yield 7.8 g (53%) of the title compound as a light tan solid.

Workup

  1. customa beige-colored slurry formed
  2. temperatureThe reaction was cooled to -78° C.
  3. customThe reaction immediately became homogeneous
  4. additionwas added
  5. customThe stirred reaction
  6. temperatureto warm slowly to 0° C.
  7. customquenched into ice (300 g) and concentrated hydrochloric acid (45 mL)
  8. extractionThe resulting mixture was extracted with CH2Cl2
  9. washThe combined extracts were washed with water
  10. dry with materialdried over anhydrous sodium sulfate overnight
  11. filtrationfiltered
  12. concentrationconcentrated
  13. concentrationThe resulting solution was concentrated in vacuo
  14. additionThe residue was treated with Et2O (300 mL)
  15. temperaturecooled to 0° C. for 1 hr
  16. customThe resulting solid was isolated by filtration
  17. washwashed with Et2O

Sources & evidence

ORD record
ord-61f54a14ad3e4306af9259fb8943a4b7
Source dataset
uspto-grants-1989_01
Patent number
US04798893

Reaction notes

Loading…