Hydrochloric Acid → (2,5-Dichlorothiophen-3-yl)boronic acid

Participants

Reaction Steps

n-Butyllithium in hexane (1.66M solution, 5.2 ml) was added dropwise to a solution of 3-bromo-2,5-dichlorothiophene (2.0 g) and triisopropoxyborane (2.4 ml) in ether (20.0 ml) at -75-65° C. for 10 minutes and the mixture was stirred at same temperature for 1 hour. The reaction mixture was poured onto 1N-hydrochloric acid (30 ml) and the mixture was extracted with ether. The separated extract layer was washed with brine, dried over magnesium sulfate and evaporated in vacuo to give (2,5-dichlorothiophen-3-yl)-dihydroxyborane (1.13 g).

Provenance & Evidence