Yield:578007-67-7 80%

Reaction Conditions:

Stage #1: 2-Aminonicotinaldehydewith sulfuric acid;iodine;acetic acid;periodic acid in water at 80; for 4 h;
Stage #2: with sodium hydroxide in water;

Steps:

36

2-Aminonicotinaldehyde (515 mg, 4.22 mmol), periodic acid (144.1 mg, 0,63 mmol) and iodine (460.2 mg, 0.43mmol) were dissolved in a mixture of acetic acid (12.0 ml), H₂O (0.6 ml) and H₂SO₄ (0.1 ml). The mixture was heated to 80⁰C for 4 h. Then it was poured into Na₂S₂O₃ (10% aq. solution), neutralized with NaOH (2N aq. solution) and extracted with EtOAc. The combined organic extracts were dried (MgSO₄), filtered and concentrated. The crude product was purified by flash chromatography; Pet. Ether, EtOAc (4:1 →1 :1) affording 842 mg (80%) the title compound. 1H NMR (CDCl₃) δ 9.81 (s, IH), 8.41 (d, IH), 8.04 (d, IH), 6.80 (bs, 2H).

References:

WO2010/97410,2010,A1 Location in patent:Page/Page column 146