Diisopropylethylamine → Ethyl(+/-)-4-(1-((3-methylquinolin-2-yl)amino)butyl)benzoate

Participants

Reaction Steps

Intermediate 2 (22.9 g, 104 mmol) was combined with 3-methylquinoline-N-oxide (Intermediate 3, 17.3 g, 109 mmol) and dichloromethane (414 mL). Diisopropylethylamine (68.0 mL, 389 mmol) was added, followed by bromotripyrrolidinophosphonium hexafluorophosphate (61.0 g, 130 mmol). The solution was stirred at room temperature for 12 h before diluting with sat. aq NaHCO3 (400 mL). The mixture was extracted with ethyl acetate (3×400 mL). The combined organics were dried over Na2SO4 and filtered, and the filtrate was concentrated under reduced pressure. Purification by silica gel flash chromatography (ethyl acetate/heptane) gave ethyl (+/−)-4-(1-((3-methylquinolin-2-yl)amino)butyl)benzoate (Intermediate 4). 1H NMR (400 MHz, CDCl3) δ 7.99 (d, J=8.2 Hz, 2 H), 7.65-7.58 (m, 2 H), 7.56-7.48 (m, 3 H), 7.43 (t, J=7.5 Hz, 1 H), 7.16 (t, J=7.4 Hz, 1 H), 5.50 (q, J=7.2 Hz, 1 H), 4.79 (d, J=7.0 Hz, 1 H), 4.35 (q, J=7.0 Hz, 2 H), 2.30 (s, 3 H), 2.04-1.83 (m, 2 H), 1.54-1.39 (m, 2 H), 1.37 (t, J=7.1 Hz, 3 H), 0.98 (t, J=7.4 Hz, 3 H).

Provenance & Evidence