Hydrochloric Acid → 4,4-Difluoro-1-[2-thienyl]-butane-1,3-dione

HRID 1721114

Reaction equation

HRID 1721114 reaction equation
[F:1][CH:2]([F:8])[C:3]([O:5]CC)=O.C[O-].[Na+].[C:12]([C:15]1[S:16][CH:17]=[CH:18][CH:19]=1)(=[O:14])[CH3:13].Cl>CCOCC>[F:8][CH:2]([F:1])[C:3](=[O:5])[CH2:13][C:12]([C:15]1[S:16][CH:17]=[CH:18][CH:19]=1)=[O:14]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 69202-AcetylthiopheneHCID 9961Ethyl difluoroacetateHCID 10942334Sodium Methoxide

Product 1

HCID 170248414,4-Difluoro-1-[2-thienyl]-butane-1,3-dione

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

Ethyl difluoroacetate (1.84 g,14.8 mmol) was placed in a 100 mL round bottom flask and dissolved in ether (5 mL). To the stirred solution was added 25 weight % sodium methoxide (3.39 g, 15.7 mmol) followed by 2-acetylthiophene (1.72 g,13.6 mmol). The reaction was stirred at room temperature overnight (15.67 hours), then treated with 3N HCl (8 mL). The organic layer was collected and washed with brine, dried over MgSO4, concentrated in vacuo, and recrystallized from methylene chloride/isooctane to give a brown solid ! 1.38 g, mp 78°-80° C., 50%). 1H NMR (CDCl3) 300 MHz 14.90 (br s, 1H), 7.80 (d, J=4.0 Hz, 1H), 7.71 (d, J=3.8 Hz, 1H), 7.19 (m, 1H), 6.41 (s, 1H), 6.04 (t, J=54.2 Hz, 1H); 19F NMR (CDCl3) 300 MHz: -126.98 (d); M+204.

Workup

  1. customThe organic layer was collected
  2. washwashed with brine
  3. dry with materialdried over MgSO4
  4. concentrationconcentrated in vacuo
  5. customrecrystallized from methylene chloride/isooctane
  6. customto give a brown solid

Sources & evidence

ORD record
ord-d8b39c0f17d24b11b66ea775823f1a34
Source dataset
uspto-grants-1996_04
Patent number
US05508426

Linked notes

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