Potassium thiocyanate → 2-Oxo-2-[3-(trifluoromethyl)phenyl]ethyl thiocyanate

HRID 1257469Notes

Reaction equation

Br[CH2:2][C:3]([C:5]1[CH:10]=[CH:9][CH:8]=[C:7]([C:11]([F:14])([F:13])[F:12])[CH:6]=1)=[O:4].[S-:15][C:16]#[N:17].[K+]>C(O)C.O>[O:4]=[C:3]([C:5]1[CH:10]=[CH:9][CH:8]=[C:7]([C:11]([F:14])([F:13])[F:12])[CH:6]=1)[CH2:2][S:15][C:16]#[N:17]

Participants

Conditions

Temperature: 80 °C

Procedure

A solution of 2-bromo-1-[3-(trifluoromethyl)phenyl]ethanone (20 g) in ethanol (100 mL) was heated to 60-70° C., and aqueous solution (10 mL) of potassium thiocyanate (8 g) was added dropwise. The reaction mixture was heated at 80° C. for 10 min, and the mixture was stirred at room temperature for 4 hr and diluted with water. The precipitate was collected by filtration, dissolved in ethyl acetate and dried over anhydrous sodium sulfate. The solvent was evaporated to give 2-oxo-2-[3-(trifluoromethyl)phenyl]ethyl thiocyanate (14 g) as a solid. This solid (10 g) was dissolved in acetic acid (50 mL), and 48% hydrogen bromide-acetic acid solution (10 mL) was added. The reaction mixture was heated at 70-80° C. for 3 hr, and the solvent was evaporated under reduced pressure. The residue was dissolved in ethyl acetate and water, sodium bicarbonate was added, and the mixture was adjusted to pH 7. The ethyl acetate layer was separated, washed with saturated brine and dried over sodium sulfate, and the solvent was evaporated. The residue was purified by column chromatography (carrier: silica gel, eluent: hexane-ethyl acetate) to give the title compound (4.2 g) as a colorless solid.

Workup

filtrationThe precipitate was collected by filtration
dissolutiondissolved in ethyl acetate
dry with materialdried over anhydrous sodium sulfate
customThe solvent was evaporated

Sources & evidence

ORD record: ord-3341c4da1a1d4f2dadc8a996b0ce95c9
Source dataset: uspto-grants-2013_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08461348B2

Reaction notes

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