Cystamine Dihydrochloride → Fluorescein cystamine

Participants

Reaction Steps

Cystamine dihydrochloride (68 mg, 0.301 mmol) and DIEA (110 μL, 2.1 eq.) were dissolved in DMF (10 mL), followed by addition of NHS-fluorescein, a mixture of 5- and 6-carboxyfluorescein (300 mg, 0.634 mmol) and the resulting reaction mixture was stirred overnight at room temperature. Then it was diluted with ethyl acetate and washed three times with water and one time with brine. The extract was dried over anhydrous sodium sulfate, concentrated under reduced pressure, redissolved in small amount of methanol and ethyl acetate, and then triturated with diethyl ether to obtain 140 mg of fluorescein-cystamine adduct as a bright orange solid.

Provenance & Evidence