Ammonium Chloride → [5-(4-Isopropyl-piperazine-1-carbonyl)-1H-indol-2-yl]-(4-methanesulfonyl-piperazin-1-yl)-methanone

Participants

Reaction Steps

To a solution of 1.70 g (4.8 mmol) 5-(4-isopropyl-piperazine-1-carbonyl)-1H-indole-2-carboxylic acid hydrochloride in 17 mL N,N-dimethylformamide, were added 1.94 g (6.0 mmol) O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate, 1.0 g (6.0 mmol) 1-methylsulfonyl-piperazine and 4.1 mL (3.1 g, 24.0 mmol) N,N-diisopropylethylamine. After 2 h the solution was poured into 10% aqueous ammonium chloride solution, the phases were separated and the aqueous phase was extracted ten times with ethyl acetate. The combined organic layers were washed three times with water, brine, dried over magnesium sulfate, filtered and evaporated. The residue was flash-chromatographed twice on silica gel with dichloromethane:methanol (9:1 v/v) as eluant to give 1.45 g (65%) of the desired compound as a light-brown foam. MS (ISP): 462.1 (M+H)+.

Provenance & Evidence