Trifluoroacetamide → N-(4-Bromobenzenesulfinyl)-2,2,2-trifluoroacetamide

HRID 1485629Notes

Reaction equation

HRID 1485629 reaction equation
C([Li])CCC.[F:6][C:7]([F:12])([F:11])[C:8]([NH2:10])=[O:9].[Br:13][C:14]1[CH:19]=[CH:18][C:17]([S:20](Cl)=[O:21])=[CH:16][CH:15]=1>O1CCCC1>[Br:13][C:14]1[CH:19]=[CH:18][C:17]([S:20]([NH:10][C:8](=[O:9])[C:7]([F:12])([F:11])[F:6])=[O:21])=[CH:16][CH:15]=1

Participants

5

Reactant 3

HCID 67717TrifluoroacetamideHCID 109775414-Bromobenzenesulfinic chlorideHCID 178418339Butyllithium

Product 1

HCID 118863945N-(4-Bromobenzenesulfinyl)-2,2,2-trifluoroacetamide

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

Thionyl chloride (0.53 mL) is added to an ice-cooled solution of 4-bromobenzenesulfinic acid (400 mg) in dichloromethane (15 mL) under an argon atmosphere. The reaction mixture is stirred for 2 h at 0° C., warmed to room temperature, and stirred for an additional 30 min. The mixture is concentrated and the residue is co-evaporated twice with toluene to give crude 4-bromobenzenesulfinic chloride, which is dissolved in tetrahydrofuran (3 mL) and cooled to −78° C. n-Butyllithium (1.6 M in hexane; 2.26 mL) is added to 2,2,2-trifluoroacetamide (205 mg) in tetrahydrofuran (3 mL) at −78° C. and the reaction mixture is stirred for 10 min. The mixture is added to the 4-bromobenzenesulfinic chloride solution at −78° C. and the reaction mixture is stirred for 1 h. The cooling bath is removed and the reaction is quenched by addition of water and brine. The aqueous layer is extracted with ethyl acetate and the combined extracts are washed with brine and concentrated in vacuo to give the title compound which is used for the next step without further purification. LC (method 1): tR=0.92 min; Mass spectrum (ESI+): m/z=314 [M−H]−.

Workup

  1. stirringthe reaction mixture is stirred for 1 h
  2. customThe cooling bath is removed
  3. customthe reaction is quenched by addition of water and brine
  4. extractionThe aqueous layer is extracted with ethyl acetate
  5. washthe combined extracts are washed with brine
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-71ecedd187a243679ed991c3ef07ecef
Source dataset
uspto-grants-2016_08
Patent number
US09422312B2

Reaction notes

Loading…