Pyridine → 4-Pentyl-2-cyanopyridine

Beteiligte Stoffe

Reaktionsschritte

To (1-Oxy-pyridin-4-yl)-methanol (5g, 0.04 mol) in a solution of dichloromethane (10 mL) and pyridine (10 mL) was added acetic anhydride (12.2 mL, 0.12 mol) and the reaction mixture was stirred for 16 h at room temperature. The reaction mixture was then poured into water and extracted with dichloromethane (200 mL) and then washed with brine (100 mL). The crude product obtained (4.27 g, 64%) was taken without purification for the next reaction. To the crude product (4.27 g, 25.6 mmol) in DCM (25 mL) and trimethylsilyl cyanide (3.40 mL, 25.6 mmol), dimethylcarbamyl chloride (2.35 mL, 25.6 mmol) was added slowly and then the reaction mixture was stirred at room temperature over night. Aqueous potassium carbonate (100 mL, 10%) was added and stirred for 10 minutes. Extraction with ethyl acetate followed by removal of solvent resulted in crude product which was purified on silica gel column chromatography using 50% ethyl acetate in hexanes to obtain cyanopyridine 10a (R9=acetoxymethylene) (2.37 g, 48%).

Herkunft & Nachweise