Hydrochloric Acid → HCID 22316969, compound

Participants

Reaction Conditions

Reaction Steps

n-Butyllithium (2.5 M solution in hexane, 20 ml, 50 mmol) was added dropwise to a solution of 3-bromothiophene (8.15 g, 50 mmol) in THF (20 ml) at -78° C. under an argon atmosphere. The resulting solution was stirred at -78° C. for 45 min, and then added to a solution of triisopropyl borate (9.4 g, 50 mmol) in THF at -78° C. over 30 min through a steel cannula. The resulting reaction mixture was stirred at room temperature for 12 h and was decomposed by the addition of 100 ml 1N HCl. The aqueous layer was extracted with ether (2×100 ml) and the combined organic layers was extracted with 1 M NaOH (3×30 ml), the aqueous extract was acidified with concentrated HCl to pH 2 and extracted with ether (3×50 ml). The combined ether extract was washed once with water, dried over MgSO4 and filtered. Removal of the solvent gave 3-thenylboronic acid as a solid (5.2 g, 80% yield).

Provenance & Evidence