Trifluoroacetic acid → 2-[6-(4-Cyclobutylpiperazin-1-yl)pyrimidin-4-yl]-4-(1H-imidazol-1-yl)-1,2-dihydro-3H-pyrazol-3-one

Participants

Reaction Conditions

Reaction Steps

16 μl (23 mg, 0.2 mmol) of trifluoroacetic acid are added to a mixture of 211 mg (1.0 mmol) of the compound from Example 5A and 250 mg (1.0 mmol) of the compound from Example 9A in 4 ml of ethyl acetate, and the mixture is stirred at 100° C. for 20 h. The reaction mixture is concentrated under reduced pressure, more ethyl acetate and trifluoroacetic acid (the same amounts as above) are added and the mixture is stirred at 100° C. for 20 h. The reaction mixture is cooled to RT, and the precipitated solid is filtered off and washed with diethyl ether. The residue is pre-purified by column chromatography on silica gel (mobile phase dichloromethane/methanol/ammonia 10/2/0.2) and purified by preparative HPLC (RP18 column; mobile phase: acetonitrile/water gradient). Yield: 137 mg (36% of theory)

Provenance & Evidence