Reaction Steps
14-tert-butoxycarbonylamino-18-(isoquinolin-1-yloxy)-2,15-dioxo-3,16-diaza-tricyclo[14.3.0.04,6]-nonadec-7-ene-4-carboxylic acid (67 mg, 0.10 mmol) was dissolved in 5 mL of THF and treated with CDI (21 mg, 0.13 mmol). (Care was taken to avoid moisture by using oven dried glassware and maintaining a dry N2 atmosphere.) After refluxing the reaction mixture for one hour, it was cooled to rt and treated sequentially with isopropylsulfonamide (16 mg, 0.13 mmol) and DBU (20 mg, 0.13 mmol). After stirring for 24 h at rt, the THF was removed by rotary evaporation. The residue was partitioned between ethyl acetate and pH 4 buffer. The organic phase was dried (MgSO4) and concentrated in vacuo to give the crude product. Flash chromatography (1–5% MeOH/methylene chloride) gave 50 mg (71%) of the desired product. Further purification by preparative HPLC (YMC ODS-A, S5, 20×100 mm, gradient: 60% to 100% B) gave 30 mg (43%) of [18-(isoquinolin-1-yloxy)-2,15-dioxo-4-(propane-2-sulfonylaminocarbonyl)-3,16-diaza-tricyclo[14.3.0.04,6]nonadec-7-en-14-yl]-carbamic acid tert-butyl ester as a white powder: 1H NMR (300 MHz, CD3Cl3) δ 1.22 (S, 9H), 1.31 (d. J=6.6 Hz, 3H), 1.41 (d, J=6.9 Hz, 3H), 1.20–1.96 (m, 11H), 2.30 (q, J=8.4 Hz, 1H), 2.56 (m, 1H), 2.69 (m, 2H), 3.69 (m, 1H), 4.03 (m, 1H), 4.29 (m, 1H), 4.62 (m, 2H), 4.97–5.06 (m, 2H), 5.68 (q, J=9.5 Hz, 1H), 5.91 (s, 1H), 6.76 (s, 1H), 7.23 (m, 1H), 7.45 (t, J=7.7 Hz, 1H), 7.63 (t, J=8.1 Hz, 1H), 7.71 (d, J=8.1 Hz, 1H), 7.97 (d, J=5.9 Hz, 1H), 8.17 (d, J=8.1 Hz, 1H), 9.89 (s, 1H). LC-MS (Method A, retention time: 3.79 min), MS m/z 670 (M++1).
