Hydrogen Peroxide → 5-Ethoxy-2-fluorophenol

Participants

Reaction Conditions

Reaction Steps

A solution of 56.3 g 4-ethoxy-fluorophenol in 200 ml THF was treated with 84.0 ml pentamethyl-diethylentriamine, cooled to −78° C., then slowly treated with 251 ml 1.6 M n-butyllithium solution in hexane. The reaction mixture was stirred at −78° C. for 3 hrs and then slowly treated with 89.7 ml trimethyl borate. After stirring for 15 min at −78° C., the solution was warmed up to r.t., stirred for an additional 2 hrs and cooled to 0° C. To the mixture were then added dropwise 63.2 ml acetic acid. After stirring for 30 min, 68.3 ml 30% aqueous hydrogen peroxide solution were added slowly. The reaction mixture was warmed up to r.t., stirred overnight and subsequently treated with 200 ml saturated sodium sulfite solution. The mixture was diluted with water and extracted with hexanes. The organic layer was washed with water and brine, dried over MgSO4, filtrated and concentrated to give 60.3 g 5-ethoxy-2-fluoro-phenol as a light brown liquid which was used for the next step without further purification.

Provenance & Evidence