Triphenylphosphine → 4,7-difluoro-3-((3aS,4S,6aR)-5-fluoro-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-yl)-3H-imidazo[4,5-c]pyridine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

(3S,4R,6aR)-5-fluoro-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-ol (5-6) (290 mg, 1.6 mmol, 1 equiv) was dissolved in dry THF (15 mL). Triphenylphosphine (620 mg, 2.4 mmol, 1.5 equiv) was added followed by 4,7-difluoro-1H-imidazo[4,5-c]pyridine (1-4) (370 mg, 2.4 mmol, 1.5 equiv). The mixture was cooled to 0° C. and DIAD (0.46 mL, 2.4 mmol, 1.5 equiv) was added dropwise. The resulting mixture was stirred at ambient temperature for 2 hours. Upon disappearance of the starting material, the solvent was removed at reduced pressure and the yellow residue was purified by flash chromatography (40 g SiO2, 15-100% EtOAc in hexanes) to yield 4,7-difluoro-1-(3aS,4S,6aR)-5-fluoro-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-yl)-1H-imidazo[4,5-c]pyridine (5-7) and 4,7-difluoro-3-((3aS,4S,6aR)-5-fluoro-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-yl)-3H-imidazo[4,5-c]pyridine (5-8) as a 1:1 regioisomeric mixture. 1H NMR (5-7) (500 MHz, CDCl3): δ 7.91 (s, 1H); 7.86 (t, J=2.0 Hz, 1H); 5.80 (s, 1H); 5.66 (s, 1H); 5.38 (m, 1H); 4.75 (q, J=5 Hz, 1H); 1.56 (s, 3H); 1.37 (s, 3H). LRMS m/z (M+H) 311.9 found, 312.1 required. 1H NMR (5-8) (500 MHz, CDCl3): δ 7.99 (s, 1H); 7.89 (t, J=2.0 Hz, 1H); 5.80 (s, 1H); 5.66 (s, 1H); 5.38 (m, 1H); 4.75 (q, J=5 Hz, 1H); 1.56 (s, 3H); 1.37 (s, 3H). LRMS m/z (M+H) 311.9 found, 312.1 required.

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