Trifluoroacetic acid → methyl (2S)-5-cyclobutoxy-6-[1-(3-methoxypiperidin-4-yl)-1H-pyrazol-4-yl]-2-methyl-1,2,3,4-tetrahydroquinoline-1-carboxylate

Participants

Reaction Steps

A 25-mL round-bottom flask was charged with (2S)-methyl 6-(1-(1-(tert-butoxycarbonyl)-3-methoxypiperidin-4-yl)-1H-pyrazol-4-yl)-5-cyclobutoxy-2-methyl-3,4-dihydroquinoline-1(2H)-carboxylate (40 mg, 0.07 mmol), dichloromethane (3 mL), and trifluoroacetic acid (1 mL). The resulting solution stirred for 1 h at room temperature. The reaction mixture was concentrated under vacuum. The residue was purified by Prep-HPLC with the following conditions: Column: Xbridge RP C18, 19×150 mm, 5 um; Mobile Phase water (0.05% trifluoroacetic acid), acetonitrile (15% to 43% acetonitrile in 9 min, flow rate: 20 mL/min); Detector, 254/220 nm. The fractions were combined and concentrated under vacuum and the residue was further purified via reverse phase chromatography (acetonitrile/water (0.05% ammonium bicarbonate)=5/95-95/5). The fractions were combined, concentrated and lyophilized to afford methyl (2S)-5-cyclobutoxy-6-[1-(3-methoxypiperidin-4-yl)-1H-pyrazol-4-yl]-2-methyl-1,2,3,4-tetrahydroquinoline-1-carboxylate (14 mg, 43%) as an off-white solid. 1H NMR (300 MHz, CD3OD) δ ppm 1.10-1.20 (m, 3H), 1.25-1.50 (m, 2H), 1.50-1.70 (m, 1H), 1.95-2.52 (m, 8H), 2.80-3.10 (m, 2H), 3.10-3.35 (m, 4H), 3.55-3.90 (m, 6H), 4.05-3.15 (m, 1H), 4.40-4.65 (m, 2H), 7.18-7.35 (m, 2H), 7.93 (s, 1H), 8.01-8.12 (m, 2H). MS (ESI, pos. ion) m/z 455 [M+H]+.

Provenance & Evidence