2-(2,5-Dioxopyrrolidin-1-yl)-1,1,3,3-tetramethylisouronium tetrafluoroborate → 19-{1-tert-Butoxycarbonyl-3-[2-(2-{2-[2-(2-carboxyethoxy)ethoxy]ethoxy}ethoxy)ethylcarbamoyl]propyl-carbamoyl}nonadecanoic acid tert-butyl ester

Participants

Reaction Steps

2-(19-tert-Butoxycarbonylnonadecanoylamino)pentanedioic acid 1-tert-butyl ester 5-(2,5-dioxopyrrolidin-1-yl) ester (0.56 g, 0.822 mmol) was dissolved in THF (20 mL), 3-(2-{2-[2-(2-amino-ethoxy)-ethoxy]ethoxy}ethoxy)propionic acid (0.22 g, 0.82 mmol) in THF (20 mL) was added and the mixture stirred at RT for 3 h. LCMS indicated the reaction was finished (MS: m/z 831 (M+1)) and the reaction mixture was used directly for the following reaction with TSTU.

Provenance & Evidence