Reaction Steps
To a slurry of N-(3-{(3β)-cholest-5-en-3-yl[(2-nitrophenyl)sulfonyl]amino}propyl)-6-[(2,4-dinitrophenyl)amino]hexanamide (19, 164 mg, 0.180 mmol) and K2CO3 (270 mg, 1.954 mmol) in N,N-dimethylformamide (20 mL) was added thiophenol (80 μL, 0.777 mmol). After stirring at 23° C. for 18 h, the mixture was filtered and solvent was removed in vacuo. The crude product was purified by flash column chromatography (MeOH /triethylamine/CH2Cl2, 2:5:100) to afford 4 (77 mg, 59%) mp 165-166° C.; 1H NMR (500 MHz, CDCl3) δ 9.11 (d, J=2.6 Hz, 1H), 8.53 (br s, 1H), 8.25 (dd, J=2.5 Hz, J=9.5 Hz, 1H), 6.99 (t, J=4.3, 1H), 6.90 (d, J=9.5 Hz, 1H), 5.29 (d, J=4.8 Hz, 1H), 3.42-3.38 (m, 2H), 3.34 (dt, J=5.8 Hz, J=5.9 Hz, 2H), 2.74 (t, J=6.1 Hz, 2H), 2.39-2.34 (m, 1H), 2.23-2.17 (m, 3H), 2.04-1.92 (m, 4H), 1.84-0.98 (m, 32H), 0.95 (s, 3H), 0.90 (d, J=6.5 Hz, 3H), 0.85 (d, J=2.1 Hz, 3H), 0.84 (d, J=2.1 Hz, 3H), 0.65 (s, 3H); 13C NMR (75.5 MHz, CDCl3) δ 172.5, 148.5, 141.5, 136.2, 130.5 (×2), 124.5, 121.2, 114.7, 58.4, 56.9, 56.3, 50.4, 45.5, 43.6, 42.5, 40.3, 39.9, 39.7, 39.3, 38.1, 37.2, 36.6, 36.4, 36.0, 32.1, 32.0, 29.7, 29.2, 28.7, 28.4, 28.2, 26.8, 25.3, 24.4, 24.0, 23.0, 22.7, 21.2, 19.6, 18.9, 12.0; IR (film) νmax 3362, 3295, 2934, 2867, 1622, 1336 cm−1; CI m/z 722.5229 (MH+, C42H68N5O5 requires 722.5220).
