Sodium Iodide → 6-Methoxy-4-oxo-8-piperazin-1-yl-4H-chromene-2-carboxylic acid (4-morpholin-4-yl-phenyl)-amide

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Reaction Steps

Into a 50 mL round bottom flask equipped with a reflux condenser, nitrogen inlet and magnetic stirrer is placed 50 mg (0.115 mmol, 1.0 equiv.) of 6-Methoxy-8-(4-methyl-piperazin-1-yl)-4-oxo-4H-chromene-2-carboxylic acid (4-morpholin-4-yl-phenyl)-amide (Example 31) and 10 mL of 1, 2 dichloroethane. To this solution is then added via syringe 49 mg, 37 μL (0.345 mmol, 3.0 equiv.) of 1-chloroethyl chloroformate. A precipitate forms, indicating formation of an intermediate. The reaction is heated to reflux for 3 days, whereupon an analysis of an aliquot by LC/MS indicates only a trace of product has formed. At this time 52 mg (0.345 mmol, 3.0 equiv.) of sodium iodide are added to the refluxing reaction. LC/MS analyses then progressively show formation of demethylated product over 5 additional days. The reaction is then cooled, concentrated on a rotary evaporator, then dried over K2CO3 as a suspension in methylene chloride containing methanol, removal of solids by filtration, followed by flash chromatography of the solution, using a gradient of 5 to 20% methanol in methylene chloride, gives 34 mg (64%) of the pure product as a reddish solid.

Provenance & Evidence