Fluorescein 5-isothiocyanate → HCID 178513895, compound

Participants

Reaction Steps

EDA-folate analog 6a was condensed with fluorescein isothiocyanate (FITC, 7) in the presence of DIPEA and 1,1,3,3-tetramethylguanidine (TMG) in DMSO, giving 8a (218 g), which was collected as a precipitate from 1:1 ACN/MTBE. Folate-FITC 8a was purified by reverse phase column chromatography (Biotage C18 cartridge, 100 mM sodium phosphate buffer/acetonitrile as mobile phase). Fractions containing 8a were detected by UV absorption (280 nm) and pooled. Volatile solvents were evaporated, and the residue was desalted by reverse phase column chromatography (Biotage C18 cartridge, water/acetonitrile as mobile phase). Volatile solvents were evaporated, and the residue was lyophilized to give 47 g (22% overall) of 8a. HPLC (Nova-Pak C18 column, 10 mM ammonium acetate/acetonitrile as mobile phase) indicated that the material was greater than 98% pure, and bisfluorescein derivative IIIa (n=1) was not detectable by UV or fluorescence.

Provenance & Evidence