N,N-Dimethylethylenediamine → 3-Aminocoumarin

Participants

Reaction Steps

241 mg 3-carboxy-6 chloro-7-hydroxy coumarin (1 mmol) dissolved in the mixture of 5 ml THF and 5 ml DMF was added 200 ul diisopropylethylamine (DIEA, 1.1 mmol) and 330 mg O—(N-succinium)-N,N,N′,N′-tetramethyl uronium tetrafluoroborate (TSTU, 1.1 mmol). After stirring at room temperature for 20 minutes under nitrogen atmosphere, the reaction mixture was added 400 ul of DIEA and 460 ul benzyl chloromethyl ether (BOM-Cl) and stirred for another 2 hours at room temperature. The resulted mixture was then pulled high vacuum for 2 hours and 1 ml THF, 480 ul 2-dimethyaminoethylamine was added into the solution afterwards. After the reaction mixture was allowed to react at room temperature for 1 hour, the crude product was pulled high vacuum again overnight and purified on a silica gel column (chloroform:methanol=95:5 as eluent). 190 mg colorless solid was obtained as product, 44% yield. 1H NMR (CDCl3, ppm): 2.32 (d, 6H), 2.56 (t, 2H), 2.16 (t, 2H), 4.76 (s, 2H), 5.46 (s, 2H), 7.33 (m, 7H), 7.68 (s, 1H), 8.76 (s, 1H). MS: C22H23O5N2Cl, 430.3 calculated; 431.2 (M+1) found.

Provenance & Evidence