To a solution of 8-amino-1-methyl-4,5-dihydro-1H-1,7,9-triaza -cyclopenta[a]naphthalene-3-carboxylic acid M2 (0.08 mmol) in dry DMF (4 mL), HOBT.NH3 (0.164 mmol), TBTU (0.164 mmol) and DIEA (0.328 mmol) were added. The mixture was stirred at rt for 24 h then the solvent was evaporated. The residue was suspended in 10 mL of water, filtered, washed with water and dried in vacuo, providing the title compound (55% yield). ESI (+) MS: m/z 244 (MH+). 1H NMR: 2.73 (t, J=7.44, 2H), 3.00 (t, J=7.44, 2H), 4.04 (s, 3H), 6.94 (bs, 1H), 7.35 (bs, 1H), 7.73 (s, 1H), 7.96 (s, 1H), 7.76 (bs, 3H).
