2,2,6,6-Tetramethylpiperidine → HCID 90310803, compound

Participants

Reaction Conditions

Reaction Steps

To a 500 mL round-bottomed flask were added a stir bar, dry THF (60 mL) and 2,2,6,6-tetramethylpiperidine (8.0 mL, 47 mmol). The flask was cooled to −78° C. (bath temp) and then treated with 2.5 M n-BuLi in hexanes (18.0 mL, 45 mmol) over 2 min. The resultant mixture was stirred for 5 min and then allowed to warm to 0° C. After 35 min, the mixture was re-cooled to −78° Celsius and treated with B(O-iPr)3 (10.20 mL, 44 mmol) over 4 min. After 16 min, a solution consisting of 1-cyclobutyl-3-fluoro-2-methoxybenzene (7.24 g, 40.2 mmol) and dry THF (20.0 mL) was added over the course of 6 min and stirring continued for 3.5 h before adding HOAc (8 mL). The mixture was then poured into water and stirred for 5 min. The aqueous mixture was then extracted with EtOAc (200 mL), the extract dried over MgSO4, filtered and concentrated to dryness to give (4-cyclobutyl-2-fluoro-3-methoxyphenyl)boronic acid as an off-white solid (8.08 g, 90%). The crude product was used directly in the next synthetic step.

Provenance & Evidence