Methyl 4,4,4-trifluoro-3-oxobutanoate → 1-tert-Butyl-3-cyclobutyl-4-trifluoromethyl-1,7-dihydro-pyrazolo[3,4-b]pyridin-6-one

Participants

Reaction Conditions

Reaction Steps

To a stirring solution of crude 2-tert-butyl-5-cyclobutyl-2H-pyrazol-3-ylamine (2.0 g, 10.4 mmol) in AcOH (10 mL) was added 4,4,4-trifluoro-3-oxo-butyric acid methyl ester (3.5 g, 20.7 mmol). The reaction was then heated to 110° C. for 18 hr, at which time the reaction was cooled to room temperature, concentrated under reduced pressure, diluted with EtOAc, and quenched with a saturated aqueous solution of NaHCO3. The organic layer was dried over MgSO4, filtered through a fritted funnel, and concentrated under reduced pressure to give the title compound (3.2 g, quantitative yield). This material was used without further purification. LRMS m/z (APCl) 314 (M+1); 500 MHz 1H NMR (CDCl3) δ 6.66 (s, 1H), 3.78 (dddd, J=8.3, 8.3, 8.3, 8.3 Hz, 1H), 2.49-2.39 (m, 2H), 2.34-2.26 (m, 2H), 2.06-1.85 (m, 2H), 1.75 (s, 9H).

Provenance & Evidence