Acetic Acid → 1-(Ethynyl)-2-(4-fluoro-3-methylphenyl)-4,4,6,6-tetramethyl-1-cyclohexene

HRID 6521Notes

Reaction equation

HRID 6521 reaction equation
C[Si]([C:5]#[C:6][C:7]1[C:12]([CH3:14])([CH3:13])[CH2:11][C:10]([CH3:16])([CH3:15])[CH2:9][C:8]=1[C:17]1[CH:22]=[CH:21][C:20]([F:23])=[C:19]([CH3:24])[CH:18]=1)(C)C.C(O)(=O)C.[F-].C([N+](CCCC)(CCCC)CCCC)CCC>C1COCC1.CCOCC>[C:6]([C:7]1[C:12]([CH3:14])([CH3:13])[CH2:11][C:10]([CH3:16])([CH3:15])[CH2:9][C:8]=1[C:17]1[CH:22]=[CH:21][C:20]([F:23])=[C:19]([CH3:24])[CH:18]=1)#[CH:5]

Participants

6

Reactant 3

HCID 176Acetic AcidHCID 2724141Tetrabutylammonium FluorideHCID 197939071-((Trimethylsilyl)ethynyl)-2-(4-fluoro-3-methylphenyl)-4,4,6,6-tetramethylcyclohexene

Product 1

HCID 197938991-(Ethynyl)-2-(4-fluoro-3-methylphenyl)-4,4,6,6-tetramethyl-1-cyclohexeneYield 98%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of the product from Example 1, Step D above (5 g, 14.6 mmol), and acetic acid (1.3 ml, 21.9 mmol) in THF (15 ml) at 0° C. is added tetrabutylammonium fluoride in THF (1M, 21.9 ml, 21.9 mmol). The resulting solution is stirred for 12 hours at room temperature, diluted with ether and washed with saturated ammonium chloride solution. The ether fraction is dried over MgSO4, and the solvent is removed under reduced pressure. Purification by silica gel chromatography (100% hexane) provides 3.9 g (98%) of 1-(ethynyl)-2-(4-fluoro-3-methylphenyl)-4,4,6,6-tetramethyl-1-cyclohexene: 1H NMR δ=1.0 (s,6), 1.22 (s,6), 1.45 (s,2), 2.15 (s,2), 2.25 (s,3), 2.75 (s,1), 6.95 (t,1), 7.15 (m,2).

Workup

  1. washwashed with saturated ammonium chloride solution
  2. dry with materialThe ether fraction is dried over MgSO4
  3. customthe solvent is removed under reduced pressure
  4. customPurification by silica gel chromatography (100% hexane)

Sources & evidence

ORD record
ord-30b768947e544f58a83c823717346385
Source dataset
uspto-grants-1993_09
Patent number
US05248830

Reaction notes

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