Trifluoroacetic acid → [6-Chloro-5-(1-isopropyl-piperidin-4-yloxy)-1H-indol-2-yl]-piperazin-1-yl-methanone

Participants

Reaction Steps

To a cold (0° C.) solution of 4-[6-chloro-5-(1-isopropyl-piperidin-4-yloxy)-1H-indole-2-carbonyl]-piperazine-1-carboxylic acid tert-butyl ester (example 3, 547 mg, 1.0 eq.) in dichloromethane was added trifluoroacetic acid (1.23 mL, 10 eq.) dropwise. The reaction mixture was stirred 3 h at room temperature. The mixture was concentrated in vacuo and the residue was partitioned between ethyl acetate and a saturated aqueous sodium carbonate solution. The aqueous phase was extracted with ethyl acetate and the combined organic phases were dried over sodium sulfate, filtered and the solvents removed in vacuo. The residue was purified by flash chromatography on silica gel with a 90:9:1 dichloromethane/methanol/ammonia eluant to afford 413 mg (94%) of the title compound as a light-yellow solid.

Provenance & Evidence