Triethylamine → Coumarin 343 aminohexanoic Acid

Participants

Reaction Steps

Coumarin 343 (5 mmol, Aldrich No. 393029) and each 5.5 mmol of 4-aminohexanoic acid methyl ester and HBTU (O-Benzotriazole-N,N,N′,N′-tetramethyl-uronium-hexafluoro-phosphate) as well as 11 mmol triethylamine were dissolved in 100 ml DMF and stirred for 1.5 h at room temperature. The solvent is removed by evaporation on a rotary evaporator and the residuum is dissolved in trichloromethane. Residual HBTU is removed by extraction with water with 0.5 mol/l hydrochloric acid. The organic solvent is separated and evaporated to dryness in a rotary evaporator. The crude product (2.37 g) is purified by flash chromatography (silica gel 60, Merck, No: 11452134001) with a mobile phase consisting of trichloromethane:ethyl acetate 2:1 (v/v) (yield: 1.03 g).

Provenance & Evidence