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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of 108 mg (0.50 mmol) of 1,4-dimethyl-6-pentyl-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine in 3 mL of chloroform was added 70.7 mg (0.25 mmol) of 1,3-dibromo-5,5-dimethylhydantoin in portions at 0° C. The reaction mixture was stirred at 0° C. for 30 min. The reaction was quenched by the addition of 5 mL of sat aq. NaHCO3. The mixture was extracted with chloroform and the combined organic layer was washed with brine and dried over MgSO4. The concentrated residue was purified by flash chromatography on a silica gel column (20 1.7 cm). Elution with 100:1 hexanes/ethyl acetate gave the product as a yellow oil: yield 136 mg (92%); silica gel TLC Rf 0.65 (8:1:1 hexanes/ethyl acetate/methanol); 1H NMR (CDCl3) δ 0.89 (t, 3H, J=7.2 Hz), 1.33-1.38 (m, 4H), 1.66 (quint, 2H, J=7.6 Hz), 2.16 (s, 3H), 2.77 (t, 2H, J=8.0 Hz), 2.82-2.87 (m, 5H) and 3.40 (t, 2H, J=8.0 Hz); 13C NMR (CDCl3) δ 14.1, 19.5, 22.6, 25.2, 28.4, 31.8, 33.0, 38.1, 52.4, 110.9, 120.4, 141.1, 156.8 and 161.8; mass spectrum, m/z 297.1 and 299.1 (M+H)+ (theoretical 297.1 and 299.1); mass spectrum (APCI), m/z 297.0968 and 199.0937 (M+H)+ (C14H22N2Br requires 297.0966 and 299.0946).

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