Reaction Steps
Lithium 4-(3-amino-4-formylphenoxy)butanoate (50 mg), HBTU (80 mg) and DMF (2 mL) were combined in a 20 mL glass vial and stirred at ambient temperature. After 30 minutes, N1-(2,4-dinitrophenyl)ethane-1,2-diamine (Oakwood, 45 mg) was added in one portion and the reaction was stirred at ambient temperature overnight. The reaction mixture was diluted with EtOAc, washed successively with dilute aq. citric acid, water, sat. aq.NaHCO3, water, and sat. aq.NaCl, dried over Na2SO4, filtered and concentrated under reduced pressure, affording the title compound as a yellow solid. Rf: 0.18 (SiO2, EtOAc). MS (ESI+): m/z 432.20 (MH+). H-NMR (400 MHz, DMSO-d6): 1.914 (2H, quint, J=7.0 Hz), 2.224 (2H, t, J=7.0 Hz), 3.349 (2H, q, J=6.0 Hz), 3.538 (2H, q, J=6.0 Hz), 3.928 (2H, t, J=6.4 Hz), 6.165 (1H, s), 6.176 (1H, dd, J=2.4, 10.0 Hz), 7.133 (1H, br.s), 7.268 (1H, d, J=10.0 Hz), 7.371 (1H, d, J=8.4 Hz), 8.167 (1H, t, J=5.8 Hz), 8.250 (1H, dd, J=2.8, 8.8 Hz), 8.835 (1H, d, J=2.8 Hz), 8.913 (1H, t, J=5.6 Hz), 9.599 (1H, s). C-NMR (100 MHz, DMSO-d6): 24.489, 31.436, 37.331, 42.745, 66.782, 98.040, 104.339, 112.751, 115.130, 123.472, 123.564, 129.725, 134.731, 137.484, 148.305, 152.824, 163.873, 172.251, 191.400.
