4-Toluenesulfonyl chloride → 4-Chloro-2-(difluoromethyl)-1-{[5-(2,4-difluorophenyl)-1,3,4-oxadiazol-2-yl]methyl}-1H-indole-5-carbonitrile

Participants

Reaction Steps

To a suspension of [4-chloro-5-cyano-2-(difluoromethyl)-1H-indol-1-yl]acetic acid (0.020 g, 0.070 mmol) in DCE (3 mL), under N2, was added EDCl (0.016 g, 0.081 mmol) and stirred at rt. After 5 min, 2,4-difluorobenzohydrazide (0.014 g, 0.081 mmol) was added and stirring was continued at rt. After 30 min, TsCl (0.016 g, 0.084 mmol) and P-BEMP (loading 2.2 mmol/g, 0.127 g, 0.28 mmol) were added and the mixture was heated at 100° C. for 20 min. The reaction was monitored by LC/MS. Subsequently, the mixture was heated at 120° C. for 30 min. Additional TsCl (0.020 g, 0.105 mmol) and P-BEMP (0.127 g, 0.28 mmol) were added and the mixture was heated at 120° C. another 20 min. Upon cooling, the resin was filtered off and washed with EtOAc. The filtrate was concentrated in vacuo and the residue was purified by flash chromatography (10-70% EtOAc-hexanes gradient). The product was crystallized from CH2Cl2-hexanes to afford the title compound as a white solid (0.011 g, 38% yield): MS (ES) m/z 421 (M+1).

Provenance & Evidence