Diisopropylethylamine → N-(4-bromo-1-methyl-1H-pyrazol-3-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide

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Reaction Steps

A solution of pyrazolo[1,5-a]pyrimidine-3-carboxylic acid (165.5 mg, 1.014 mmol, 1.01 eq), 4-bromo-1-methyl-1H-pyrazol-3-amine (177.4 mg, 1.008 mmol, 1.0 eq), N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)uranium hexafluorophosphate (497 mg, 1.31 mmol, 1.30 eq), N,N-diisopropylethylamine (0.25 mL, 1.4 mmol, 1.4 eq), and 4-dimethylaminopyridine (33.8 mg, 0.277 mmol, 0.27 eq) in 5 mL N,N-dimethylformamide was heated at 50° C. for 4 days. The reaction mixture was partitioned between ethyl acetate and water, and the organic portion washed with brine, dried over magnesium sulfate and concentrated. The crude product was purified by flash chromatography on silica gel (20 to 80% ethyl acetate in dichloromethane (containing 5% methanol)) to yield 203.6 mg (63%) of N-(4-bromo-1-methyl-1H-pyrazol-3-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide. LCMS (ESI) m+H=321.1; 1H NMR (400 MHz, CD3OD) δ: 9.16 (d, 1H), 8.84 (d, 1H), 8.68 (s, 1H), 7.76 (s, 1H), 7.28 (d of d, 1H), 3.88 (s, 3H).

Provenance & Evidence