Diisopropylethylamine → 6-Fluoro-3-[((2S)-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]pyrazolo[1,5-a]pyrimidine

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Reaction Steps

The lithium salt of 6-fluoropyrazolo[1,5-a]pyrimidine-3-carboxylate (117 mg, 0.63 mmol) (may be prepared as described in Description 16) was weighed into a vial with HATU (247 mg, 0.65 mmol), suspended in DMF (2 ml) and treated with DIPEA (0.170 ml, 0.97 mmol). This mixture was stirred about 15 min at ambient temperature. (3S)-3-Methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine (may be prepared as described in Description 2) (100 mg, 0.32 mmol) was added and stirring was continued for 3 h at ambient temperature. The reaction mixture was partitioned between DCM and sat. aq. NaHCO3 solution (10 ml each). The layers were separated (hydrophobic frit) and the aqueous layer was washed with further DCM (2×5 ml). The combined organic layers were concentrated to leave an orange gum. Purification by MDAP gave the title compound (112 mg, 0.24 mmol, 73% yield) as an orange solid.

Provenance & Evidence