4-Toluenesulfonyl chloride → 5-benzyl-N-(2-(5-chloro-1H-indol-3-yl)ethyl)-1,3,4-oxadiazole-2-carboxamide

Participants

Reaction Conditions

Reaction Steps

To a suspension of 2-(2-(5-chloro-1H-indol-3-yl)ethylamino)-2-oxoacetic acid (0.350 mg; 1.31 mmol) in chloroform (20 mL) was added thionyl chloride (0.955 mL; 13.12 mmol) and the mixture was stirred at 80° C. for 3 h and was then evaporated to dryness. The resulting 2-(2-(5-chloro-1H-indol-3-yl)ethylamino)-2-oxoacetyl chloride (0.180 g, 0.631 mmol) was dissolved in dichloromethane (12 mL) and a mixture of triethylamine (0.355 mL; 2.53 mmol) and 2-phenylacetic acid hydrazide (0.092 g; 0.600 mmol) in dichloromethane (2 mL) was added at 0° C. The mixture was stirred at room temperature for 3 days and p-toluenesulfonyl chloride (0.122 g, 0.631 mmol) was added. The resulting mixture was stirred 18 h at room temperature, diluted with dichloromethane, washed with an aqueous solution of sodium carbonate, and concentrated under reduced pressure. The residue was purified by flash column chromatography on silica gel (eluent 12 to 100% ethyl acetate in heptane) to give 0.006 g (2.5%) of 5-benzyl-N-(2-(5-chloro-1H-indol-3-yl)ethyl)-1,3,4-oxadiazole-2-carboxamide as a white solid.

Provenance & Evidence