Ethyl-(2-{[1-(5-nitro-1H-indol-2-yl)-methanoyl]-amino}-ethyl)-carbamic acid dimethyl-ethyl ester → 1H-indole-2,5-dicarboxylic acid bis-{[2-(2-ethylamino-ethylcarbamoyl)-1H-indol-5-yl]-amide}

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Reaction Conditions

Reaction Steps

Compound 78 (127 mg, 0.336 mmol) was reduced to 79 by hydrogenation according to general procedure A in example 10. A mixture of above amine DS13a and 1H-indole-2,5-dicarboxylic acid bis-(pentafluorophenyl-amide) 74 (45 mg, 0.084 mmol) in 2 ml of anhydrous DMF under argon was stirred at 55° C. overnight. The solvent was evaporated to dryness. The residue was dissolved in 5 ml of TFA/anisole (8:2) and the mixture was kept at room temperature for 1 h. The product was precipitated by ether and purified by HPLC described in general procedure B in example 10 to give 76 (22 mg, 40%). ESI MS: 662.27 (M+H+), 331.64 (M/2+H+).

Provenance & Evidence