Reaction #63303

Reaction equation

phosphine

2,2,3,3,4,4,4-heptafluoro-N-[4-(2-hydroxyethyl)phenyl]butanamide

carbon tetrabromide

triphenylphosphine

→

2,2,3,3,4,4,4-heptafluoro-N-[4-(2-bromoethyl)phenyl]butanamide

Yield 54.5%

Solvents

tetrahydrofuran

diethyl ether

Conditions

Workup

1. 1
   Temperaturewas cooled in ice
2. 2
   OtherThe precipitate was removed by filtration
3. 3
   Concentrationthe filtrate concentrated in vacuo
4. 4
   OtherThe residue was purified by chromatography on silica gel
5. 5
   Washeluted with dichloromethane

Procedure

A mixture of 2,2,3,3,4,4,4-heptafluoro-N-[4-(2-hydroxyethyl)phenyl]butanamide (25 g), carbon tetrabromide (51 g), diethyl ether (140 mL) and tetrahydrofuran (140 mL) was cooled in ice and treated with triphenylphosphine (39.3 g), portionwise. When addition of the phosphine was complete, the reaction mixture was allowed to warm to room temperature and stirred for 2 hours. The precipitate was removed by filtration and the filtrate concentrated in vacuo. The residue was purified by chromatography on silica gel, eluted with dichloromethane to give 16.2 g of 2,2,3,3,4,4,4-heptafluoro-N-[4-(2-bromoethyl)phenyl]butanamide as a white solid.

Source