Sulfuric Acid → Trifluoromethyl 1-tosylimidazol-5-ylmethyl ketone

HRID 27616Notes

Reaction equation

HRID 27616 reaction equation
C([O:3][C:4](=[CH:9][C:10]1[N:14]([S:15]([C:18]2[CH:24]=[CH:23][C:21]([CH3:22])=[CH:20][CH:19]=2)(=[O:17])=[O:16])[CH:13]=[N:12][CH:11]=1)[C:5]([F:8])([F:7])[F:6])C.S(=O)(=O)(O)O>CCOCC.O>[S:15]([N:14]1[C:10]([CH2:9][C:4]([C:5]([F:8])([F:6])[F:7])=[O:3])=[CH:11][N:12]=[CH:13]1)([C:18]1[CH:19]=[CH:20][C:21]([CH3:22])=[CH:23][CH:24]=1)(=[O:16])=[O:17]

Participants

5

Reactant 2

HCID 1118Sulfuric AcidHCID 542746752-Ethoxy-1,1,1-trifluoro-3-(1-tosyl-5-imidazolyl)prop-2-ene

Product 1

HCID 23343204Trifluoromethyl 1-tosylimidazol-5-ylmethyl ketone

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 3283Diethyl EtherSolvent

Conditions

Temperature
25 °C

Procedure

A mixture of 20 mmole of 5-acetoxymethyl-1-tosylimidazole and 22 mmole of triphenylphosphine in 100 ml of benzene is heated at reflux temperature for 4 days. The solid which separates on cooling is filtered, washed with benzene, dried under reduced pressure then added slowly to a solution of 20 mmole of sodium amide in 100 ml of liquid ammonia (prepared by adding 0.46 g of sodium to liquid ammonia in the presence of a catalytic amount of ferric nitrate). After stirring for 10 minutes the ammonia is evaporated under a stream of nitrogen. To the residue is added 100 ml of anhydrous benzene and the heterogeneous mixture is heated at reflux for 10 minutes. The solid residue is filtered, and to the filtrate containing salt-free 1-tosyl-5-imidazolylmethylidene triphenylphosphorane is added 5.10-2M of ethyl trifluoroacetate. The reaction mixture is heated at reflux temperature under nitrogen for 12 hours. Concentration of the solvent leaves a residue which is distilled under high vacuum to afford 2-ethoxy-1,1,1-trifluoro-3-(1-tosyl-5-imidazolyl)prop-2-ene. A solution of 3 g of 2-ethoxy-1,1,1-trifluoro-3-(1-tosyl-5-imidazolyl)prop-2-ene in 50 ml of ether is treated with a solution of 1 M of sulfuric acid in 50 ml of water. The reaction mixture is stirred for 1/2 hour at 25° C. The ether phase is separated, washed with brine, dried over magnesium sulfate and concentrated to give trifluoromethyl 1-tosylimidazol-5-ylmethyl ketone.

Workup

  1. customThe ether phase is separated
  2. washwashed with brine
  3. dry with materialdried over magnesium sulfate
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-46782a8cdde2443cad27615d203e90a8
Source dataset
uspto-grants-1980_09
Patent number
US04221914

Reaction notes

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