3-Iodo-6-(phenylethynyl)pyridazine synthesis

Yield:1338493-54-1 58%

Reaction Conditions:

with sulfuric acid;acetic acid;sodium iodide in water;acetonitrile at 70; for 8 h;

Steps:

151.1

Step 1: 3-Iodo-6-(phenylethynyl)pyridazine To a solution of 100 mg (0.466 mmol) of 3-chloro-6-(phenylethynyl)pyridazine in 5 ml of acetonitrile were added sodium iodide (209 mg, 1.4 mmol, 3 equiv.), acetic acid (56 mg, 53.3 ml, 0.93 mmol, 2 equiv.), and 95% sulfuric acid (4.6 mg, 2.5 ml, 0.47 mmol, 1 equiv.). The orange solution was stirred for 8 hours at 70° C. and then left to cool overnight. After standard workup with ethyl acetate/water, the residue was adsorbed onto 4 g of silicagel and purified by flash chromatography over a 20 g silicagel column over a heptane to 50% ethyl acetate in heptane gradient to yield 82 mg (58% yield) of the title compound as a crystalline light yellow solid, MS: m/e=307.1 (M+H⁺).

References:

US2011/251169,2011,A1 Location in patent:Page/Page column 124