Boron tribromide → 6-[(2-chloro-4-hydroxy-phenyl)-1-hydroxy-1-trifluoromethyl-propyl]-4-methyl-4H-benzo[1,4]oxazin-3-one

Participants

Reaction Conditions

Reaction Steps

A solution of 6-[2-(2-chloro-4-methoxy-phenyl)-1-hydroxy-1-trifluoromethyl-propyl]-4-methyl-4H-benzo[1,4]oxazin-3-one (4.9 g, 11.4 mmol) in dichloromethane (130 ml) was cooled to −70° C. A 1 M solution of boron tribromide in dichloromethane (45.6 ml) was added dropwise (25 min) and the mixture was stirred at −70° C. for 1.5 h. The ice bath was removed and the mixture was stirred at r.t. for 3 h. The reaction mixture was poured on a mixture of ice water and sat aq NaHCO3 solution, extracted three times with dichloromethane. The organic phases were washed with water and dried (MgSO4) and concentrated. The product was dried under high vacuum to give the title compound (4.9 g) as an off-white solid. MS (m/e)=416.1 [M+H+].

Provenance & Evidence