Hydrochloric Acid → 953411-01-3

Participants

Reaction Conditions

Reaction Steps

To a solution of thieno[2,3-b]pyridine (0.50 g, 3.7 mmol) in THF (25 mL) at about −78° C. was added n-BuLi (1.6 M in hexane, 2.5 mL, 4.1 mmol) dropwise over about 10 min. After about 45 min, added triisopropyl borate (0.93 mL, 4.1 mol). Stirred for about 1 hour at about −78° C. then at about 0° C. for about 30 min. 10% aqueous HCl (10 mL) was added and the ice bath was removed. After about 30 min, EtOAc (30 mL) was added. The reaction mixture was filtered to remove a precipitate that was washed with additional water and EtOAc. The combined layers were separated and the aqueous layer was extracted with additional EtOAc (2×30 mL). The combined organic layers were washed with brine, dried over anhydrous Na2SO4, decanted, and concentrated to get a solid that was triturated with EtOAc and heptane then filtered to give thieno[2,3-b]pyridin-2-ylboronic acid (0.043 g, 6%); RP-HPLC (Table 1, Method g) Rt 1.67 min, m/z (ESI+) 180.1 (M+H)+.

Provenance & Evidence