4-(4-bromo-1-methyl-1H-pyrazol-3-yl)pyridine → 5-(1-methyl-3-(pyridin-4-yl)-1H-pyrazol-4-yl)-2,3-dihydroinden-1-one O-benzyl oxime

Participants

Reaction Steps

To (E)-1-(benzyloxyimino)-2,3-dihydro-1H-inden-5-ylboronic acid (3.00 g; Example 2, Step 4) in 32 mL acetonitrile and 8.0 mL water was added 4-(4-bromo-1-methyl-1H-pyrazol-3-yl)pyridine (2.00 g; Example 3, Step 3). The solution was deoxygenated by bubbling nitrogen through the solution for 10 min. To the resulting mixture was added 5.62 g potassium carbonate, 10 mL N,N-dimethylformamide, and 290 mg tetrakis(triphenyphosphine)palladium(0). The mixture was then refluxed for 8 hours (over the course of this time a small portion of catalyst was added twice). The cooled reaction mixture was filtered through celite and the filter cake was washed with ethyl acetate. The filtrate was washed with water, brine, dried over sodium sulfate, filtered, and evaporated under vacuum to yield 5.1 g crude product as an oil. The crude material was purified by chromatography, eluting with ethyl acetate to afford 2.50 g (80% yield) product as a light yellow foam. 1H NMR (CDCl3) was consistent with the desired structure. LC/MS showed one peak with a M+1 molecular ion of m/z 395.2 by positive ESI.

Provenance & Evidence