Potassium Carbonate → (R)-4-[(S)-1-(6-cyano-3,3-dimethyl-2,3-dihydro-indole-1-carbonyl)-propyl]-2-methyl-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a suspension of (R)-1-(2-chlorobutanoyl)-3,3-dimethylindoline-6-carbonitrile (0.1 g, 0.36 mmol), (R)-2-methyl-piperazine-1-carboxylic acid tert-butyl ester (0.072 g, 0.36 mmol) in acetonitrile (2.5 mL) was added potassium carbonate (0.049 g, 0.36 mmol) and the reaction heated to 50° C. for 48 h followed by 80° C. for 24 h and 60° C. for 36 h. The reaction mixture was then diluted with ethyl acetate and washed with water. The organics were separated, dried with sodium sulfate and concentrated. The residue was purified by flash column chromatography on silica gel; eluting with 20-30% ethyl acetate in heptane to give (R)-4-[(S)-1-(6-cyano-3,3-dimethyl-2,3-dihydro-indole-1-carbonyl)-propyl]-2-methyl-piperazine-1-carboxylic acid tert-butyl ester (0.023 g). MS: [M+H]+=441.

Provenance & Evidence