Triisopropyl borate → HCID 57900174, compound

Participants

Reaction Steps

4.77 ml (12 mmol) of 2.5 M n-Butyl lithium in hexane was added dropwise to a solution of 3166 mg (10.0 mmol) of 2-chloro-6,7-dihydro-9-bromopyrido[3,2-b]thieno[2,3-d]oxepine in 100 ml of tetrahydrofuran at −76° C. After stirring for 10 min, 3.21 ml (14.0 mmol) of triisopropylborate was added. The mixture was kept at −76° C. for 20 min, then 10 ml of saturated aqueous ammonium chloride were added and the mixture was mixed with 360 ml of water. The product was extracted with 150 ml of ethyl acetate. The organic layer was washed with 100 ml of water, 100 ml of brine and dried over anhydrous sodium sulfate. The solution was filtered and concentrated in vacuum to afford a residue which was then triturated with a mixture of hexane and ethyl ether (1:1). A precipitate was filtered, washed with cold ethyl ether, hexane and dried in vacuum to give 2-Chloro-6,7-dihydro-pyrido[3,2-b]thieno[2,3-d]oxepine-9-boronic acid. Yield 2.20 g (78%). MS: (ESI+)=282.1.

Provenance & Evidence