Veratrole → N-Boc-(2,3-dimethoxyphenyl)-4-piperidinylmethanone

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of n-BuLi (2.5M, 452 mL) in hexane was added to a solution of veratrole (149 g, 1.08 mol) in anhydrous tetrahydrofuran (1.2 L) over 10 minutes at −78° C. under nitrogen. The resulting solution was stirred at 0° C. for 1 hour and room temperature for 4 hours. A solution of 4-[(methoxymethylamino)carbonyl]-1-piperidinecarboxylic acid, 1,1-dimethylethyl ester (15) (275 g, 1.01 mol) in tetrahydrofuran (800 mL) was added to the reaction slurry at −65° C. over 20 minutes. The mixture was warmed to room temperature, stirred for 18 hours and quenched with saturated ammonium chloride (1 L). After stirring for 1 hour, the phases were separated and the aqueous layer was extracted with ethyl ether (1 L). The combined organic solutions were washed with brine (2 L) and dried (MgSO4). The mixture was filtered and the filtrate was concentrated (30° C./20 torr) to a residue (413 g). The solution may be used directly in Scheme L, step a, Example 108.

Herkunft & Nachweise