Potassium Iodide → 2-Iodo-8-(4-methoxyphenyl)-[1,2,4]triazolo[1,5-a]pyridine

Participants

Reaction Steps

A solution of potassium iodide (5.4 g, 32 mmol, 3.9 equiv) and sodium nitrite (1.73 g, 25.1 mmol, 3.00 equiv) in water (10 mL) was added over 5 min to a solution of 8-(4-methoxyphenyl)-[1,2,4]-triazolo[1,5-a]pyridin-2-amine (2.01 g, 8.36 mmol, 1 equiv) and p-toluenesulfonic acid (7.3 g, 38 mmol, 4.6 equiv) in acetonitrile at 24° C. After 19 h, the reaction mixture was diluted with ethyl acetate (250 mL), and the resulting solution was washed sequentially with water (2×120 mL) and saturated aqueous sodium chloride solution (120 mL). The collected organic was dried over magnesium sulfate, filtered, and concentrated in vacuo. Purification by flash column chromatography (20→30% ethyl acetate in heptane) provided product as a light yellow solid (1.92 g, 65% yield). 1H NMR (400 MHz, CDCl3), δ: 8.46 (dd, J=6.8, 1.0 Hz, 1 H), 7.96 (m, 2 H), 7.59 (dd, J=7.4, 1.1 Hz, 1 H), 7.01-7.06 (m, 3 H), 3.86 (s, 3 H).

Provenance & Evidence