Triethylamine → 2-(6-Hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acid

Participants

Reaction Steps

Under argon atmosphere, to a solution of 2-azidoethylamine (16) (˜50%, 1H NMR) (synthesized by the method described in Non-Patent Document: R. Srinivasan, L. P. Tan, H. Wu, P. Yang, K. A. Kalesh, S. Q. Yao, Org. Biomol. Chem. 2009, 7, 1821-1828) (200 mg, ˜1.16 mmol) in dichloromethane (5 mL) were successively added triethylamine (70.0 μL, 502 μmol) and fluorescein isothiocyanate isomer I (FITC, 17, commercial product) (90%, HPLC) (100 mg, 231 μmol) at room temperature. After stirring for 21 hours at the same temperature, the reaction solution was concentrated under reduced pressure using an evaporator. The residue was purified by flash column chromatography (silica-gel 30 g, dichloromethane/methanol=9/1) to give 1-(2-azidoethyl)-3-(5-fluoresceinyl)thiourea (18) (109 mg, 229 μmol, 99.2%) as an orange solid.

Provenance & Evidence