Reaction Steps
To a solution of 4-amino-2-butyl-1-(2-hydroxy-2-methylpropyl)-7-methoxycarbonyl-1H-imidazo[4,5-c]quinoline S7 (37 mg, 0.1 mmol, 1.0 equiv) and 2,5-dioxopyrrolidin-1-yl 4-[(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)methyl]cyclohexanecarboxylate (66 mg, 0.20 mmol, 2.0 equiv) in DMF (2.0 mL) at 25° C. was added NEt3 (40 μL, 0.30 mmol, 3.0 equiv) in one injection. The reaction was heated at 50° C. for 24 h. The solvent was then removed in vacuo and the solid was redissolved in 1:9 MeOH/EtOAc (50 mL), washed successively with saturated NaHCO3 solution (15 mL), H2O (15 mL) and saturated aqueous NaCl (15 mL) and the organic layer concentrated. TLC and MS analysis indicated existence of both the imidazoquinoline starting material and the desired product. Purification by flash column chromatography on silica gel (CH2Cl2-1/9 MeOH/CH2Cl2, gradient) afforded the title compound 550 (40 mg, 68%) as a white solid: 1H NMR (CD3OD, 600 Hz) δ1.04 (t, J=7.2 Hz, 3H), 1.11-1.18 (m, 2H), 1.26 (br s, 6H), 1.51-1.66 (m, 4H), 1.68-1.85 (m, 3H), 1.91 (pent, J=7.2 Hz, 2H), 3.13 (t, J=7.2 Hz, 2H), 3.40 (d, J=7.2 Hz, 2H), 6.83 (s, 2H), 7.98 (d, J=9.0 Hz, 1H), 8.41 (d, J=9.0 Hz, 1H), 8.66 (s, 1H); 13C NMR (CD3OD, 150 Hz) δ 12.9, 22.3, 27.2, 28.5, 28.7, 29.5, 29.6, 36.6, 43.1, 45.4, 51.4, 54.9, 71.1, 119.9, 121.4, 123.7, 126.5, 126.6, 126.6, 128.0, 128.8, 130.5, 133.9, 135.2, 142.5, 144.3, 158.2, 159.9, 160.0, 166.8, 171.4; MS (APCI+): calcd C32H40N5O6 [M+H]+ 590.3. found 590.3.
