1,2-Dimethoxyethane → 4-(4-Cyanoquinoline-2-yl)-2-hydroxy-benzoic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

2-Chloroquinoline-4-carbonitrile (0.15 g), 2-methoxymethoxy-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)benzoic acid methyl ester (0.26 g), tetrakis(triphenylphosphine)palladium (0.045 g) and sodium carbonate (0.16 g) were suspended in a mixed solvent of dimethoxyethane (2 mL) and water (0.5 mL), and the resulting mixture was stirred at 150° C. for 30 minutes using microwave reactor (Biotage). To the reaction mixture was added ethyl acetate, and the mixture was filtered through a Celite pad. The filtrate was poured into water. The organic layer was washed with water and brine, and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel (eluent: n-hexane/ethyl acetate=100/0-66/34) to give 4-(4-cyanoquinoline-2-yl)-2-hydroxy-benzoic acid methyl ester (0.1 g). To a mixed solution of this compound (0.1 g) in tetrahydrofuran (4 mL), ethanol (1 mL) and water (1 mL) was added lithium hydroxide monohydrate (0.060 g), and the mixture was stirred at room temperature overnight. To this reaction mixture was added 2 mol/L hydrochloric acid (2.8 mL), and the mixture was stirred at 50° C. for 10 hours. After the reaction mixture was cooled to room temperature, the precipitated solid was collected by filtration, and dried under reduced pressure to give the title compound (0.068 g).

Provenance & Evidence