4-Toluenesulfonyl chloride → N-(2-(5-chloro-1H-indol-3-yl)ethyl)-5-cyclohexyl-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 (0.920 mg; 3.45 mmol) in chloroform (50 mL) was added thionyl chloride (2.51 mL; 34.50 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 (0.480 g; 1.68 mmol) was dissolved in dichloromethane (12 mL) and a mixture of triethylamine (0.945 mL; 6.73 mmol) and cyclohexanecarboxylic acid hydrazide (0.232 g; 1.60 mmol) in dichloromethane (8 mL) was added at 0° C. The mixture was stirred at room temperature for 2 h and p-toluenesulfonyl chloride (0.324 g, 1.68 mmol) was added. The resulting mixture was stirred overnight 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 0.0088 g (1.40%) of N-(2-(5-chloro-1H-indol-3-yl)ethyl)-5-cyclohexyl-1,3,4-oxadiazole-2-carboxamide as a white solid.

Provenance & Evidence