Sodium Dithionite → 4-Bromo-2-(2,2-dimethoxyethyl)aniline

Beteiligte Stoffe

Reaktionsschritte

Compound 66 (75 mg, 0.259 mmol) was dissolved in anhydrous ethanol (10 mL) in a dry argon purged flask fitted with a magnetic stir bar and condenser. Sodium dithionite (158.8 mg, 0.776 mmol) and sodium bicarbonate (130.6 mg, 1.554 mmol) are added to the flask and mixture heated to reflux for 24 hours. After cooling to room temperature, the reaction was quenched by the addition of H2O (10 mL) and the ethanol removed under reduced pressure. The resulting aqueous layer was transferred to a separatory funnel and extracted with ethyl acetate (three times). The combined organic layers were washed with brine, dried over sodium sulphate, filtered, concentrated and the residue purified via chromatography on silica gel (methanol:CH2Cl2, 2:98) to yield a brown oil, 67 (32 mg, 47.5%). 1H NMR (CDCl3) δ 2.83 (d, 2H, J=5.3 Hz), 3.38 (s, 6H), 4.48 (t, 1H, J=5.3 Hz), 6.61 (d, 1H, J=8.2 Hz), 7.13 (d, 1H, J=2.2 Hz), 7.15-7.17 (m, 1H); ESI-MS (m/z, %): 198/200 (M+−2MeO, 100%).

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