Bis(dimethylaminoethyl) ether → 7-Benzylamino-6-(4-phenylpiperidine-1-carbonyl)pyrazolo[1,5-a]pyrimidine-3-carboxylic acid

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Reaction Steps

Bis[2-(N,N-dimethylamino)ethyl]ether (4.1 mL, 25.7 mmol) was dissolved in THF (15 mL), 2 mol/L isopropylmagnesium chloride-THF solution (13.0 mL, 25.7 mmol) was added dropwise under ice-cooling, and the mixture was stirred at room temperature for 5 min. A suspension (5 mL) of 7-benzylamino-3-bromo-6-(4-phenylpiperidine-1-carbonyl)pyrazolo[1,5-a]pyrimidine (1.4 g, 2.9 mmol) obtained in step 4 in THF was added to this mixture under ice-cooling, and the mixture was stirred at room temperature for 2 hr. Carbon dioxide gas was bubbled into the reaction mixture for 30 min under ice-cooling, and the reaction mixture was added dropwise to ice-cooled 1 mol/L hydrochloric acid (100 mL). The mixture was stirred at room temperature for 1 hr, and the precipitate was collected by filtration, and washed with water (50 mL) to give the title compound (0.9 g, 67%).

Provenance & Evidence