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

Participants

Reaction Steps

209 mg (1.00 mMol) 6-methoxy-benzo[d]isothiazole-3-carboxylic acid (preparation see: WO 2004/029050, Procedure N), 269 mg (1.5 mMol) 4-fluoro-3-trifluoromethyl-aniline and 1.4 ml (10 mMol) Et3N are dissolved in 5 ml of dry DMF and cooled in an ice-bath. Then a solution of 1.17 ml (50% in DMF; 2.0 mMol) propylphosphonic anhydride is added. The mixture is stirred for 15 h at rt, when another 0.58 ml of propylphosphonic anhydride are added. After 2 h, the reaction mixture is poured into water and EtOAc, the aq. phase separated off and extracted twice with EtOAc. The organic layers are washed twice with water and brine, dried (Na2SO4) and partially concentrated. Addition of hexane precipitates the title compound: m.p.: 157° C.; MS: [M+1]+=371.

Provenance & Evidence