N,N-Dimethylaniline → Ethyl 4-(7-(butyl)-3-mesityl-2,5-dimethylpyrazolo[1,5-a]pyrimidin-6-yl)butanoate

Participants

Reaction Steps

Phosphorus oxychloride (11.3 g) and N,N-dimethylaniline (3 droplets) were added to ethyl 4-(3-mesityl-2,5-dimethyl-7-oxo-4,7-dihydropyrazolo[1,5-a]pyrimidin-6-yl)butanoate (700 mg, 1.77 mmol), followed by heating under reflux for 1.5 hours. After the reaction, it was treated with ice-water, neutralized with potassium carbonate, extracted with ethyl acetate, dried over anhydrous magnesium sulfate and evaporated. The resulting reaction residue was dissolved in acetonitrile (5 ml) and n-butylamine (2 mL) was added, followed by heating under reflux for six hours. After the reaction, it was treated with water, and then neutralized with potassium carbonate, extracted with ethyl acetate, dried over anhydrous magnesium sulfate and evaporated. The residue was purified by silica gel column chromatography (10-25% ethyl acetate/hexane), to give the title compound (2.5 g) as a yellow oil.

Provenance & Evidence