Cesium carbonate → (S)-methyl 6-(2-(1-(tert-butoxycarbonyl)-4-hydroxypiperidin-4-yl)thiazol-4-yl)-5-cyclobutoxy-2-methyl-3,4-dihydroquinoline-1(2H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of (S)-methyl 5-cyclobutoxy-2-methyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4-dihydroquinoline-1(2H)-carboxylate (0.109 g, 0.273 mmol), tert-butyl 4-(4-bromothiazol-2-yl)-4-hydroxypiperidine-1-carboxylate (0.090 g, 0.248 mmol), XPhos Precatalyst 2nd Generation (0.019 g, 0.025 mmol), and cesium carbonate (0.242 g, 0.743 mmol) in 1,4-dioxane (1.0 mL) and water (0.2 mL) was heated at 100° C. for 2.5 h. The reaction mixture was cooled to room temperature, filtered through a pad of Celite, and concentrated. The residue was purified via column chromatography on silica gel (Biotage 25 g column, gradient elution with 5-50% ethyl acetate-hexane) to afford (S)-methyl 6-(2-(1-(tert-butoxycarbonyl)-4-hydroxypiperidin-4-yl)thiazol-4-yl)-5-cyclobutoxy-2-methyl-3,4-dihydroquinoline-1(2H)-carboxylate (0.128 g, 93%). MS (ESI, pos. ion) m/z 558 [M+H]+.

Provenance & Evidence