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

Temperatur

-78 °C

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%.

1. temperatureto warm to −20° C. over 3 h
2. customRemoval of volatiles
3. customgave an aqueous solution that
4. extractionwas extracted with DCM
5. washthe combined organic phases were then washed with brine
6. dry with materialdried over Na2SO4
7. concentrationconcentrated in vacuo

ORD-Eintrag

ord-a0f53afc9c454528be29c1e7c46f6753

Quelldatensatz

uspto-grants-2010_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07795247B2