Hydrochloric Acid → 6-(9-oxo-9H-acridin-4-carboxamido)hexanoic acid

Participants

Reaction Steps

4-Carboxyacridone (2.15 g, 9 mmol), was mixed with N,N-dimethylformamide (15 ml) and N,N-diisopropylethylamine (1.6 ml, 9.2 mmol) and stirred under nitrogen to give a deep yellow solution. To this was added O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium hexafluorophosphate (3.5 g, 9 mmol) and stirring continued for 2 hrs. During this time a thick yellow precipitate formed. 6-Aminohexanoic acid (1.45 g, 11 mmol) was then added and stirring continued overnight. Reverse phase chromatographic analysis (C18) (methanol:water, 80:20) indicated two spots at Rf=0.75 and Rf=0.55. The reaction mixture was then poured into 0.25M aqueous HCl (200 ml) and the precipitated product collected by vacuum filtration, washing with more dilute HCl and water. The still-damp solid was recrystallized from ethanol/water and dried under vacuum over phosphorus pentoxide to give 6-(9-oxo-9H-acridin-4-carboxamido)hexanoic acid (1.97 g, 62%). λmax (EtOH)=408, 390, 256 nm. δH (300 MHz, DMSO-d6) 1.35-1.65 (6H, m), 2.24 (2H, t), 3.40 (2H, t), 7.26-7.39 (2H, m), 7.74-7.77 (2H, m), 8.21-8.28 (2H, m), 8.44 (2H, app.d), 9.00 (1H, broad t, amide), 12.02 (broad s, D20 exch.) and 12.49 (broad s, D20 exch.). Mass spectrum: MALDI-TOF, m/z=353.15, M=353.15 for C20H21N2O4. Melting Point=218° C.

Provenance & Evidence