2-Methylquinoline → Tert-butyl 3-(2-methylquinolin-4-yl)azetidine-1-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

H2O2 (30% in H2O; 0.86 mL, 9.0 mmol) was added to a stirred solution of quinaldine 1b (400 mg, 3.0 mmol), concentrated H2SO4 (298 μL, 6.0 mmol), 1-Boc-3-(iodo)azetidine (1.58 g, 3.0 mmol) and iron(II) sulfate heptahydrate (200 mg, 0.8 mmol) in DMSO (30 mL) at room temperature. After 30 min a further portion of iron(II) sulfate heptahydrate (200 mg, 0.8 mmol) and H2O2 (30% in H2O; 0.86 mL, 9.0 mmol) was added and the mixture was stirred at room temperature for 30 min. Further H2O2 (0.86 mL, 9.0 mmol) and iron(II) sulfate heptahydrate (200 mg, 0.8 mmol) was added, and the mixture was stirred for 120 min, then poured into an ice-cold solution of NaOH and adjusted to pH >10. The aqueous was extracted with Et2O. The aqueous layer was then saturated with solid NaCl, and extracted with CHCl3 until all the product was removed from the aqueous layer. The combined organic extracts were dried (MgSO4), filtered and the solvent removed under vacuum to leave a crude residue. The residue was purified by column chromatography on silica gel using EtOAc / hexanes (1:1 to 1:0) as eluent to give the desired product 3b (450 mg, 50%) as an oil that crystallized on standing.

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