Reaction Steps
A mixture of commercially available 8-bromo-3,7-dihydro-3-methyl-7-(2-oxo-2-phenylethyl)-1H-purine-2,6-dione (42, 50 mg, 0.138 mmol), diisopropylethylamine (47 μL, 0.275 mmol) and butylamine (27 μL, 0.275 mmol) in EtOH (1 mL) was heated at 120° C. for 12 h. The reaction was cooled to room temperature, the solid was filtered off, washed with water, affording the desired product as a white solid (22 mg, 44% yield). 1H NMR (400 MHz, DMSO-d6): δ=11.57 (s, 1H), 8.04 (d, J=7.8 Hz, 2H), 7.72 (t, J=7.8 Hz, 1H), 7.60 (t, J=7.8 Hz, 2H), 6.99 (t, J=5.5 Hz, 1H), 5.62 (s, 2H), 3.32 (s, 3H), 3.32 (m, 2H), 1.51 (quint, J=7.4 Hz, 2H), 1.31 (sext, J=7.4 Hz, 2H), 0.88 (t, J=7.4 Hz, 3H); 13C NMR (125 MHz, DMSO-d6): δ=192.2, 154.6, 153.0, 150.7, 150.0, 134.1, 133.8, 128.7, 127.9, 101.7, 49.5, 41.8, 31.0, 28.2, 19.2, 13.5; IR (film): ν=3361, 3008, 2827, 1681, 1485, 1425, 1230, 746 cm−1; HRMS (ESI): m/z: calcd for C18H21N5O3Na+: 378.1542, found: 378.1545.