p-Toluenesulfonic acid monohydrate → N-[2-tert-Butyl-5-(3-oxo-cyclobutyl)-2H-pyrazol-3-yl]-2,2,2-trifluoro-acetamide

Participants

Reaction Conditions

Reaction Steps

To a stirring solution of N-[2-tert-butyl-5-(3,3-dimethoxy-cyclobutyl)-2H-pyrazol-3-yl]-2,2,2-trifluoro-acetamide (6.5 g, 18.5 mmol) in acetone (182 mL) and water (61 mL) was added p-toluenesulfonic acid monohydrate (1.8 g, 9.5 mmol) and the reaction mixture was heated to 65° C. After 1.5 hr, the reaction mixture was cooled to room temperature, diluted with CH2Cl2 (250 mL), and water (50 mL). The layers were separated and the aqueous layer was back-extracted with CH2Cl2. The combined organic layers were dried over MgSO4, filtered, and concentrated under reduced pressure. Purification of the resulting material was accomplished by trituration with isopropyl ether. The product was collected and dried under reduced pressure to yield the title compound (4.2 g, 76% yield, two crops) as a yellow solid. 400 MHz 1H NMR (CDCl3) d 7.86 (bs, 1H), 6.33 (s, 1H), 3.62 (dddd, J=7.6, 7.6, 7.6, 7.6 Hz, 1H), 3.46-3.30 (m, 4H), 1.62 (s, 9H). LRMS m/z (APCI+) 304 (M+1).

Provenance & Evidence