4,4,4-Trifluoro-1-[3-(trifluoromethyl)phenyl]butane-1,3-dione → 5-(3-Trifluoromethyl-phenyl)-7-trifluoromethyl-pyrazolo[1,5-a]pyrimidine

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Reaction Steps

A mixture of 4,4,4-trifluoro-1-(3-trifluoromethyl-phenyl)-butane-1,3-dione (10.3 g, 36.1 mmol) and commercially available 3-aminopyrazole (3.0 g, 36.1 mmol) in acetic acid (100 mL) was refluxed for 4 h and evaporated. The crude product was further purified by crystallization (ethyl acetate/hexane) to yield 5-(3-trifluoromethyl-phenyl)-7-trifluoromethyl-pyrazolo[1,5-a]pyrimidine (11.4 g, 95%) as a light yellow solid. MS (ISP) 323.3 [(M+H)+]; mp 96° C.

Provenance & Evidence