Trifluoroacetic acid → Piperidine-2(R)-carboxylic acid {4-[3-(5-chloro-2-hydroxy-phenyl)-1-(2-hydroxy-ethyl)-1H-pyrazol-4-ylethynyl]-phenyl}-amide

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Reaction Conditions

Reaction Steps

Compound 4A (8.2 g) was dissolved in dichloromethane (50 mL) and cooled to 0° C. with ice-water bath. TFA (50 mL) was added slowly to the above solution at 0° C. The mixture was stirred at 0° C. for 1.5 hour. LC-MS indicated the reaction was complete. Dichloromethane and TFA were removed with a rotavapor at rt. Dichloromethane (˜100 mL) was added to the residua and removed again. The process was repeated twice more. The resultant residua were suspended in ethyl acetate (˜50 mL). 5% Aqueous NaHCO3 and solid NaHCO3 were added slowly to neutralize any residual TFA. The mixture was filtered and the solid was washed with water and ethyl acetate. The solid was collected and dried under high vacuum in the presence of Drierite. The filtrate was collected and the organic layer was separated and dried over sodium sulfate. It was then filtered and the solvent was removed to give yellowish solid. The solid from filtration and the solid from filtrate were combined and the title compound 5A was obtained in quantitative yield. Using the same procedure for the preparation of 5A, the treatment of compound 16A (870 mg) with TFA (10 mL) in methylene chloride (10 mL) gives compound 17A in 74.0% yield. 1H NMR (DMSO-d6, 500 MHz) δ 10.68 (s, 1H), 9.95 (br s, 1H), 8.36 (s, 1H), 8.28 (s, 1H), 7.73 (d, 2H, J=8.5 Hz), 7.46 (d, 2H, J=8.5 Hz), 7.29 (d, 1H, J=9.0 Hz), 6.99 (d, 1H, J=9.0 Hz), 5.01 (s, 1H), 4.26 (s, 2H), 3.78 (d, 2H, J=4.0 Hz), 2.99 (d, 1H, J=12.0 Hz), 2.60 (t, 1H, J=11.0 Hz), 1.84 (s, 1H), 1.77 (s, 1H), 1.51 (d, 1H, J=11.0 Hz), 1.41 (m, 3H). LCMS (ESI) m/z 465.06 (MH+, 100); HPLC: tR=4.02 min.

Provenance & Evidence