Sodium Iodide → 4-bromo-1-ethyl-5-(4-phthalimidobutyl)-1H-pyrazole-3-carbonitrile

Participants

Reaction Conditions

Reaction Steps

Potassium phthalimide (954 mg, 5.15 mmol), sodium iodide (130 mg, 0.86 mmol), and DMF (5 mL) were added to 4-bromo-5-(4-chlorobutyl)-1-ethyl-1H-pyrazole-3-carbonitrile (1.0 g, 3.4 mmol, prepared as described in Parts A-E of Example 19), and the reaction was heated at 100° C. for 45 minutes under a nitrogen atmosphere and allowed to cool to ambient temperature. Water (50 mL) was added, and the resulting mixture was stirred at 0° C. A precipitate formed, was isolated by filtration, and was dissolved in chloroform. The resulting solution was dried over sodium sulfate, filtered, and concentrated under reduced pressure. An analysis by nuclear resonance spectroscopy (NMR) indicated that starting material was present. The solid was treated with potassium phthalimide (1.27 g, 6.88 mmol), sodium iodide (130 mg, 0.86 mmol), and DMF (5 mL) and heated at 90° C. for three hours. Water (50 mL) was added, and the resulting solid was isolated by filtration to provide 0.97 g of 4-bromo-1-ethyl-5-(4-phthalimidobutyl)-1H-pyrazole-3-carbonitrile as a gray, crystalline solid.

Provenance & Evidence