Trifluoroacetic acid → 8-(2,4-Difluorophenoxy)-7-(6-methyl-7-oxo-6,7-dihydro-1H-pyrazolo[3,4-c]pyridin-4-yl)quinoxalin-2(1H)-one

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Reaction Steps

Trifluoroacetic acid (0.40 mL, 5.19 mmol) was added dropwise at RT to a solution of 8-(2,4-difluorophenoxy)-7-(6-methyl-7-oxo-1-{[2-(trimethylsilyl)ethoxy]methyl}-6,7-dihydro-1H-pyrazolo[3,4-c]pyridine-4-yl)-3,4-dihydroquinoxalin-2(1H)-one (10.5 mg, 0.0190 mmol, mixture of oxidized (quinoxalin) and reduced (dihydroquinoxalin) forms from previous step) in methylene chloride (0.40 mL), and the reaction mixture was stirred at RT for 1 h. The reaction mixture was purified via preparative LCMS (XBridge C18 column, eluting with a gradient of acetonitrile/water 0.1% ammonium hydroxide, at flow rate of 60 mL/min) to give the desired product (4 mg, 50%). 1H NMR (500 MHz, DMSO-d6) δ 14.05 (br s, 1H), 12.50 (br s, 1H), 8.19 (s, 1H), 7.79 (d, J=8.4 Hz, 2H), 7.42 (d, J=8.3 Hz, 1H), 7.35 (s, 1H), 7.16-6.99 (m, 1H), 6.70-6.56 (m, 1H), 6.55-6.34 (m, 1H), 3.48 (s, 3H); LCMS calculated for C21H14F2N5O3 (M+H)+: m/z=422.1. found: 422.0.

Provenance & Evidence