Iodine → 5,6-dichloro-2-(1-t-butyloxycarbonyl-2-(S)-pyrrolidinyl)furo[3,2-b]pyridine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

5,6-Dichloro-2-iodo-3-pyridinol (750 mg, 2.6 mmol)(prepared by treatment of 5,6-dichloro-3-hydroxypyridine (Koch & Schnatterer, Synthesis 1990, 499) with I2 (ibid, p. 497), copper(I) iodide (89 mg, 0.47 mmol), bis(triphenylphosphine)palladium(II) chloride (91 mg, 0.13 mmol) and triethylamine (433 mL, 3.1 mmol) were combined in DMF (3.0 mL) and allowed to stir for 1 hour. 1-t-Butyloxycarbonyl-2-(S)-ethynylpyrrolidine (610 mg, 3.1 mmol) in DMF (1 mL) was added and the reaction mixture was heated to 60° C. for 16 hours. After cooling to ambient temperature, the reaction mixture was poured over Et2O/saturated K2CO3 solution and the phases separated. The organic phase was washed with brine:water (1:1) (4×), dried (MgSO4), concentrated and chromatographed (silica gel; EtOAc/hexane, 1:6) to afford an amber oil (408 mg, 44%): 1H NMR (CDCl3, 300 MHz) δ 1.32 and 1.45 (two br s, 9H), 1.95-2.40 (m, 4H), 3.45-3.74 (m, 2H), 5.02 (m, 1H), 6.62 (s, 1H), 7.81 (s, 1H); MS (CI/NH3) m/z: 357 (M+H)+.

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