Trifluoroacetic acid → 2-(2-methyl-3-(piperidin-4-ylamino)quinoxalin-5-yl)-6,7-dihydro-1H-pyrrolo[3,2-c]pyridin-4(5H)-one

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Reaction Steps

A solution of tert-butyl 4-((3-methyl-8-(4-oxo-4,5,6,7-tetrahydro-1H-pyrrolo[3,2-c]pyridin-2-yl)quinoxalin-2-yl)amino)piperidine-1-carboxylate (Ex. 47, 80 mg, 0.168 mmol) in DCM (1.7 mL) was stirred at 25° C. before adding TFA (12.47 μl, 0.168 mmol, Sigma Aldrich). The resulting solution was stirred for 30 min before carefully adding saturated aq. NaHCO3 (10 mL) and stirring for an additional 30 min. The reaction mixture was then concentrating under reduced pressure, and the residue was taken up in DMSO and purified by reverse-phase preparative HPLC (Phenomenex Gemini column, 10 micron, C18, 100 Å, 150×30 mm, 0.1% TFA in ACN/H2O, gradient 5% to 80%). The product-containing fractions were concentrated under reduced pressure, and the residue was loaded onto a pre-washed (MeOH, 1 volume) functionalized Si-carbonate column (Silicyle) and allowed to percolate through, providing 2-(2-methyl-3-(piperidin-4-ylamino)quinoxalin-5-yl)-6,7-dihydro-1H-pyrrolo[3,2-c]pyridin-4(5H)-one (4.3 mg, 6.8%). 1H NMR (400 MHz, DMSO-d6) δ ppm 11.92 (1H, s) 7.83-7.91 (1H, m) 7.52-7.58 (2H, m) 7.28-7.35 (1H, m) 7.11-7.16 (1H, m) 3.98-4.11 (3H, m) 3.41-3.49 (2H, m) 2.97-3.06 (2H, m) 2.89 (2H, s) 2.59-2.71 (2H, m) 2.54 (3H, s) 1.93-2.04 (2H, m) 1.43-1.59 (2H, m). m/z (ESI, +ve) 377.1 (M+H)+.

Provenance & Evidence