Reaction Steps
O-(7-Azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (254 mg, 0.668 mmol) and 2,2,3,3-tetramethylcyclopropanecarboxylic acid (95 mg, 0.668 mmol) were added to a solution of the product of Example 52 (164 mg, 0.45 mmol) and diisopropylethylamine (0.16 mL, 0.89 mmol) in CH2Cl2 (5 mL). The mixture was stirred at room temperature for 45 hours, and then concentrated under vacuum. The residue was purified by preparative HPLC on a Phenomenex® Luna® C8(2) 5 μm 100 Å AXIA column (30×75 mm), eluting with methanol: 10 mM ammonium acetate in water (10:90-95:5) to provide the title compound: 1H NMR (400 MHz, pyridine-d5, 110° C.) δ ppm 0.90 (s, 6H), 1.33 (s, 3H), 1.35 (s, 3H), 1.69 (q, J=6.1 Hz, 2H), 2.04 (s, 1H), 2.03-2.13 (m, 1H), 2.40 (td, J=10.8, 2.9 Hz, 1H), 2.64 (d, J=11.0 Hz, 1H), 2.78 (d, J=10.7 Hz, 1H), 3.33-3.44 (m, 1H), 3.43 (ddd, J=13.1, 11.0, 3.0 Hz, 1H), 3.49 (s, 2H), 3.57-3.72 (m, 2H), 4.03-4.13 (m, 1H), 6.80 (dd, J=7.5, 4.7 Hz, 1H), 7.22 (t, J=7.3 Hz, 1H), 7.27-7.33 (m, J=7.3, 7.3 Hz, 3H), 7.35-7.40 (m, 2H), 8.26 (dd, J=4.6, 1.8 Hz, 1H); MS (ESI) m/z 419 (M+H)+.
