Ethyl benzoylacetate → 1-tert-Butyl-3-cyclobutyl-4phenyl-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 (4.0 g, 20.7 mmol) in AcOH (20 mL) was added 3-oxo-3-phenyl-propionic acid ethyl ester (3.5 g, 20.7 mmol). The reaction was then heated to 110° C. for 14 hr, at which time the reaction was cooled to room temperature and concentrated under reduced pressure. Purification of the resulting material was accomplished by flash chromatography using a 75 g short Biotageo column, eluting with a gradient of 5%, 10% EtOAc/hexanes. The product-containing fractions were collected and concentrated to give the title compound (1.0 g, 15% yield) as a colorless solid. Rf=0.31 (20% EtOAc/hexanes); LRMS m/z (APCl) 322 (M+1); 500 MHz 1H NMR (CDCl3) δ 7.46-7.44 (m, 3H), 7.38-7.36 (m, 2H), 6.17 (s, 1H), 3.16 (dddd, J=7.9, 7.9, 7.9, 7.9 Hz, 1H), 2.17-2.11 (m, 2H), 1.76 (s, 9H), 1.71-1.67 (m, 4H); 125 MHz 13C NMR (CDCl3) δ 163.1, 151.0, 147.5, 141.8, 138.5, 128.9, 128.4, 128.2, 112.5, 110.6, 105.7, 59.7, 34.2, 29.2, 27.6, 18.4.

Provenance & Evidence