2,2,6,6-Tetramethylpiperidine → HCID 57517762, compound

Participants

Reaction Conditions

Reaction Steps

n-BuLi (26 mmol, 16.3 mL of a 1.6M solution in hexanes) was added dropwise to a solution of 2,2,6,6-tetramethylpiperidine (26 mmol, 4.4 mL) in THF (150 mL) at 0° C. After stirring for 30 min at 0° C., the solution was cooled to −78° C. and a solution of 2-methoxypyrazine (20 mmol, 1.93 mL) in THF (30 mL) was added dropwise. After stirring at −78° C. for 15 min, a suspension of 5-chloroisatin (10 mmol, 1.82 g) in THF (50 mL) was added. The reaction mixture was stirred at 0° C. for 2 h, then saturated ammonium chloride solution was added. The mixture was extracted three times with ethyl acetate, and the collected extracts were washed with saturated brine. The organic phase was dried over magnesium sulfate, filtered and concentrated under reduced pressure. Purification by crystallization from diethyl ether yielded 1.14 g of the required intermediate.

Provenance & Evidence