3.5.18. 7,8-Dimethoxyquinolin-3-amine (29)

TFA (0.17 mL, 2.2 mmol) was added to a solution of 28 (34.8 mg, 0.11 mmol) in CH₂Cl₂ (1.0 mL) at 0 °C, and the whole mixture was stirred at rt for 3 h. Sat. NaHCO₃ aq. was added to the mixture and the whole mixture was extracted with AcOEt. Removal of the solvent from the organic phase under reduced pressure gave a crude product, which was purified with PTLC (CHCl₃/MeOH = 30:1) to give 29 (14.0 mg, 60%) as a tan oil.

¹H NMR (500 MHz, CDCl₃) δ: 8.54 (1H, d, J = 2.7 Hz), 7.32 (1H, d, J = 9.1 Hz), 7.27 (1H, d, J = 9.1 Hz), 7.21 (1H, d, J = 2.7 Hz), 4.10 (3H, s), 3.98 (3H, s), 3.83 (2H, brs). ¹³C NMR (151 MHz, CDCl₃) δ 148.3, 143.7, 143.4, 138.5, 137.8, 125.4, 121.1, 116.5, 115.3, 61.8, 57.2. IR (KBr): 3394, 3019, 2400, 1626, 1484, 1347, 1216, 1109, 768 cm⁻¹. MS (ESI-TOF) m/z: 205 [M + H]⁺. HRMS (ESI-TOF) m/z: 205.0977, calcd for C₁₁H₁₃N₂O₂. Found: 205.0986.