Diisopropylethylamine → 5-{9-[(s)-1-Tert-butoxycarbonyl-3-(2,5-dioxo-pyrrolidin-1-yloxycarbonyl)-propylcarbamoyl]-nonyloxy}-isophthalic acid di-tert-butyl ester

Participants

Reaction Steps

5-[9-((S)-1-tert-Butoxycarbonyl-3-carboxy-propylcarbamoyl)-nonyloxy]-isophthalic acid di-tert-butyl ester (70 mg, 0.11 mmol) was dissolved in dry THF (1 ml). TSTU (40 mg, 0.13 mmol) and DIPEA (0.05 ml) was added. The mixture was stirred at room temperature under nitrogen over the weekend. The mixture was concentrated. The residue was redissolved in EtOAc and filtered. The filtrate was washed with 0.1N HCl (2×), washed with brine (1×), dried (Na2SO4) and concentrated to give a clear syrup. There was still starting material present and the TSTU-treatment was repeated followed by work up to give the title compound as a clear syrup.

Provenance & Evidence