1,3-Dibromo-5,5-dimethylhydantoin → 5-bromo-1,4-dimethyl-6-octyl-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution containing 402 mg (1.54 mmol) of 1,4-Dimethyl-6-octyl-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine in 6 mL of chloroform was added 220 mg (0.77 mmol) of 1,3-dibromo-5,5-dimethylhydantoin in five portions at 0° C. The reaction mixture was stirred at 0° C. for 30 min. The reaction mixture was quenched by the addition of 8 mL of sat aq. NaHCO3. The mixture was extracted with three 25-mL portions of chloroform. The combined organic layer was washed with brine, dried over anhydrous MgSO4, filtered, and concentrated under diminished pressure. The residue was purified via flash chromatography on a silica gel column (43×2.5 cm). Step gradient elution with 1:10 ethyl acetate-hexanes as eluent gave 5-bromo-1,4-dimethyl-6-octyl-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine as a yellow oil: yield 371 mg (71%); silica gel TLC Rf 0.65 (8:1:1 hexanes-ethyl acetate-methanol); 1H NMR (CDCl3) δ 0.81 (t, 2H, J=7.2 Hz), 1.16-1.30 (m, 10H), 1.65 (quint, 2H, J=8.0 Hz), 2.12 (s, 3H), 2.59 (t, 2H, J=8.0 Hz), 2.79-2.85 (m, 5H), 3.41 (t, 2H, J=8.0 Hz).

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