Trifluoroacetic acid → (2-(Tert-butyl-dimethyl-silanyloxy)-ethyl]-(2-iodo-4-nitro-phenyl)-amine

Beteiligte Stoffe

Reaktionsschritte

To a solution of 2-iodo-4-nitroaniline (2.0 g, 7.6 mmol) and 2-(tert-butyldimethylsilyloxy)-acetaldehyde (3.5 g, 75% purity, 15 mmol) in methanol (30 mL) was added TFA (1.5 mL) at 0° C. The reaction mixture was stirred at this temperature for 30 min before NaCNBH3 (900 mg, 15 mmol) was added in portions. The mixture was stirred for 2 h and was then quenched with water. The resulting mixture was extracted with EtOAc (30 mL×3), the combined organic extracts were dried over anhydrous Na2SO4 and evaporated under vacuum, and the residue was purified by chromatography on silica gel (5% ethyl acetate/petroleum) to afford [2-(tert-butyl-dimethyl-silanyloxy)-ethyl]-(2-iodo-4-nitro-phenyl)-amine (800 mg, 25%). 1H NMR (300 MHz, CDCl3) δ 8.57 (d, J=2.7 Hz, 1H), 8.12 (dd, J=2.4, 9.0 Hz, 1H), 6.49 (d, J=9.3 Hz, 1H), 5.46 (br s, 1H), 3.89 (t, J=5.4 Hz, 2H), 3.35 (q, J=5.4 Hz, 2H), 0.93 (s, 9H), 0.10 (s, 6H).

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