Reaction Steps
To a solution of NEt(iPr)2 (520 μL, 386 mg, 2.99 mmol), DMAP (12 mg, 0.098 mmol), and C-(3-chloropyrazin-2-yl)-C-quinolin-7-ylmethylamine (compound of Formula IV where Q1=quinolin-7-yl) (608 mg, 1.97 mmol) in dry CH2Cl2 (10 mL), cooled by ice/water, was added cyclobutanecarbonyl chloride (250 μL, 260 mg, 2.19 mmol), then the cooling bath was removed, and the reaction mixture was stirred at ambient temperature for 2.5 h. Water was added, the layers were separated, and the aqueous layer was extracted with CH2Cl2 (3×20 mL). The combined CH2Cl2 layers were washed with dilute HCl (pH 2), water, saturated NaHCO3 solution, and brine and dried over MgSO4. The crude material is chromatographed on silica gel [Jones Flashmaster, 20 g/70 mL cartridge, eluting with hexanes:EtOAc 1:1 (1-21)→1:3 (22-44)→EtOAc (45-56)], yielding the title compound as an orange foam; 1H NMR (CDCl3, 400 MHz) δ 1.81-1.91 (m, 1H), 1.91-2.03 (m, 1H), 2.11-2.23 (m, 2H), 2.23-2.35 (m, 2H), 3.12 (quint, J=8.6 Hz, 1H), 6.80 (d, J=8.0 Hz, 1H), 7.22 (d, J=8.0 Hz, 1H), 7.39 (dd, J=4.0, 8.0 Hz, 1H), 7.77 (d, J=8.6 Hz, 1H), 7.82 (d, J=8.6 Hz, 1H), 7.83 (s, 1H), 8.13 (d, J=8.4 Hz, 1H), 8.37 (d, J=2.2 Hz, 1H), 8.56 (d, J=2.2 Hz, 1H), 8.87 (dd, J=1.6, 4.0 Hz, 1H); MS (ES+): m/z 353.1/355.0 (100/39) [MH+].
