Hydrochloric Acid → (4-Formylthiophen-3-yl)boronic acid

Participants

Reaction Conditions

Reaction Steps

To a 0.5M solution of B(Oi-Pr)3 (1.2 eq) in toluene/THF 4:1 was added a solution of 2-(4-bromo-3-thienyl)-1,3-dioxolane in toluene/THF 4:1, and the mixture was then cooled to −78° C. BuLi (1.5M in hexanes; 1.2 eq) was then added over 1 h, and the solution kept at this temperature for an additional h, then allowed to warm to −20° C. over 3 h; aq 1N HCl was added and the mixture stirred for an additional h at this temperature. Removal of volatiles gave an aqueous solution that was extracted with DCM; the combined organic phases were then washed with brine, dried over Na2SO4 and concentrated in vacuo. Yield: 95%.

Provenance & Evidence