Hexane → (9-Fluoro-1-methyl-4,5-dihydro-[1,2,4]triazolo[4,3-a]quinolin-7-yl)boronic acid

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Reaction Conditions

Reaction Steps

7-Bromo-9-fluoro-4,5-dihydro-1-methyl[1,2,4]triazolo[4,3-a]quinoline (1-5, 3.90 g, 13.8 mmol) was dissolved under nitrogen atmosphere in dry THF and cooled to −78° C. A 2.5 M n-BuLi solution in hexane (V=6.60 ml, 16.6 mmol) was added dropwise and stirred at −78° C. for 30 min. Triisopropyl borate (V=4.5 ml, 19.3 mmol) was added in one portion and the temperature raised to −50° C. for additional 30 min. The mixture was allowed to warm up to 0° C. and quenched with a 1M KHSO4 solution in order to reach pH 3. The solution was basified with a 2M NaOH solution and washed twice with ethyl acetate. The water layer was neutralized with conc. HCl and the precipitate was successively washed with water and ether and dried under reduced pressure to obtain the title compound as a white solid; MS (ESI): m/z=248.04 [M+H]+.

Provenance & Evidence