Veratrole → 4-(2,3-Dimethoxybenzoyl)pyridine

Beteiligte Stoffe

Reaktionsschritte

A solution of veratrole (8.04 g, 58.2 mmol) in tetrahydrofuran (50 mL) is treated with BuLi (26 mL, 2.5 M in hexane, 65 mmol) at −70° C. After the addition is complete, the reaction mixture is permitted to warm to room temperature and stirred for 2 hours. The mixture is re-cooled to −70° C. and treated with a solution of N-methyl-N-methoxyisonicotinamide (19) (9.15 g, 55.1 mmol) in tetrahydrofuran (30 mL). The resulting slurry is permitted to slowly warm to room temperature over an hour period. When the reaction mixture reaches 0° C. it becomes homogeneous. After 3 hours at room temperature, the reaction is quenched with 10% AcOH (aqueous, 100 mL). After stirring for 45 minutes, the tetrahydrofuran is removed at reduced pressure and the residue is diluted with toluene (150 mL). After neutralization with NHCO3, the phases are separated and the organic phase is submitted to a normal workup to provide an oil. Kugelrohr distillation provides the title compound (12) as a dark oil (12.77 g, 95% yield); b.p. 130-150° C./0.05 mm Hg.

Herkunft & Nachweise