Hydroxyamine hydrochloride → 6-[4-(1,3-Benzoxazol-2-yl)-2-methoxyphenyl]pyridin-3-amine

6-[4-(1,3-benzoxazol-2-yl)-2-methoxyphenyl]-N-(diphenylmethylene)pyridin-3-amine (61 mg, 0.13 mmol) was dissolved in MeOH (2 mL) and NaOAc (25 mg, 0.31 mmol) and hydroxylamine hydrochloride (16 mg, 0.23 mmol) were added. The resulting suspension was stirred at rt for 1 h. The mixture was partitioned between CH2Cl2 and 0.1N aqueous NaOH. Aqueous layer was extracted with CH2Cl2 (3×15 mL). The combined organic layers were dried over MgSO4, filtered and concentrated. Crude mixture was adsorbed onto silica gel and purified by automated flash chromatography using an EtOAc/hexanes gradient to afford the desired 6-[4-(1,3-benzoxazol-2-yl)-2-methoxyphenyl]pyridin-3-amine: 1H NMR (CDCl3, 300 MHz) δ 8.25–8.24 (d, 1H), 7.95 (s, 2H), 7.86 (s, 1H), 7.80–7.76 (m, 2H), 7.62–7.59 (m, 1H), 7.38–7.35 (m, 2H), 7.07–7.04 (m, 1H), 4.01 (s, 3H). MS (ESI) 318 (M+H)+.