Access to Highly Substituted 7‑Azaindoles from 2‑Fluoropyridines via 7‑Azaindoline Intermediates

A versatile synthesis of 7-azaindoles from substituted 2-fluoropyridines is described. C3-metalation and 1,4-addition to nitroolefins provide substituted 2-fluoro-3-(2-nitroethyl)­pyridines. A facile oxidative Nef reaction/reductive amination/intramolecular S_NAr sequence furnishes 7-azaindolines. Finally, optional regioselective electrophilic C5-substitution (e.g., bromination or nitration) and subsequent in situ oxidation delivers highly functionalized 7-azaindoles in high overall efficiency

Anti-nicotine antibody titer and function in mice.

<p>Panel A: BALB/c mice (n = 12/gp) were immunized by IM injection with 10 µg of different nicotine Hapten-DT conjugates adjuvanted with Al(OH)₃ (40 µg Al³⁺) + CpG 24555 (50 µg) on days 0, 28 and 42. Plasma was collected on day 54 and anti-nicotine antibody levels determined by ELISA (Panel A). On day 56 animals received an IV injection of ³H-nicotine (0.05 mg/kg) and plasma and brains collected. Panel B shows nicotine levels in plasma (ng-eq/mL), and Panel C shows nicotine levels in brain (ng-eq/g).</p

General scheme for addition of different linkers to Hapten 7.

<p>General scheme for addition of different linkers to Hapten 7.</p

Synthesis of Hapten 8.

<p>Synthesis of Hapten 8.</p

Structures of different linker-modified nicotine hapten.

<p>Structures of different linker-modified nicotine hapten.</p

Synthesis of Hapten 5.

<p>Synthesis of Hapten 5.</p

Synthesis of Hapten 9.

<p>Synthesis of Hapten 9.</p

Synthesis of Hapten 10.

<p>Synthesis of Hapten 10.</p

Nicotine and hapten structures.

<p>The thioacetate of Hapten 8 was deprotected to the thiol for coupling with DT.</p

Anti-nicotine antibody titer and function in mice.

<p>Panel A: BALB/c mice (n = 12/gp) were immunized by IM injection with 10 µg of different nicotine Hapten-DT conjugates adjuvanted with Al(OH)₃ (40 µg Al³⁺) + CpG 24555 (50 µg) on days 0, 28 and 42. Plasma was collected on day 54 and anti-nicotine antibody levels determined by ELISA (Panel A). On day 56 animals received an IV injection of ³H-nicotine (0.05 mg/kg) and plasma and brains collected. Panel B shows nicotine levels in plasma (ng-eq/mL), and Panel C shows nicotine levels in brain (ng-eq/g).</p