Water → 6-Hydroxy-benzo[d]isothiazole-3-carboxylic acid (4-fluoro-3-trifluoromethyl-phenyl)-amide

Participants

Reaction Conditions

Reaction Steps

A suspension of 252 mg (0.68 mMol) 6-methoxy-benzo[d]isothiazole-3-carboxylic acid (4-fluoro-3-trifluoromethyl-phenyl)-amide in 15 ml CH2Cl2 is cooled in an ice-bath, then 20 ml of a 1 M solution of BBr3 in CH2Cl2 are added. The suspension is stirred for 3 days at 45° C., the resulting solution is cooled, poured into water and EtOAc, the aq. layer is separated off and extracted twice with EtOAc. The organic layers are washed twice with water and sat. NaHCO3, dried (Na2SO4) and concentrated. Chromatography (Combi Flash; acetone/hexane 1:95→2:3) gives the title compound: MS: [M−1]=355; TLC(hexane/acetone 2:1): Rf=0.46.

Provenance & Evidence