Reaction Steps
A solution of compound S (13.9 g, 46.4 mmol) in anhydrous 1,4-dioxane (232 mL) was treated with (S)-(−)-3-(dimethylamino)-pyrrolidine (7.50 mL, 60.3 mmol) at 100° C. under N2 for 10 minutes. The solution was concentrated, and the residue was purified using a Biotage 40M amine column using a gradient of 20-50% ethyl acetate/hexanes. The fractions containing compound 132 were combined and concentrated by rotary evaporation, dissolved in acetonitrile:water (1:1, 50 mL), and then lyophilized to afford compound 132 as a pale yellow powder (12.81 g, 70% yield). 1H NMR (CDCl3, 400 MHz) d: 8.30 (dd, 1H, J=1.5 Hz), 8.00 (dd, 1H, J=1.5 Hz), 6.95 (d, 1H, J=2.0 Hz), 6.88 (d, 1H, J=3.0 Hz), 6.72 (q, 1H, J=4.5 Hz), 3.92 (s, 3H), 3.66 (q, 1H, J=4.0 Hz), 3.48 (m, 3H), 3.21 (m, 2H), 2.78 (s, 1H), 2.26 (s, 6H), 2.12 (q, 1H, J=6.0 Hz), 1.84 (m, 1H), 1.29 (t, 3H, J=7.0 Hz); 13C NMR (CDCl3, 400 MHz) d: 165.5, 158.8, 158.1, 155.7, 151.1, 151.0, 150.6, 140.3, 117.9, 112.2, 110.6, 107.3, 107.1, 65.4, 55.9, 54.4, 49.1, 44.5, 30.3, 28.6, 15.2; ESMS m/z: 395.1 [M+H+]; Calculated for C22H26N4O3: C, 66.99; H, 6.64; N, 14.20. found: C, 66.81; H, 6.66; N, 14.14.
