Ethanol → 6-Methoxypyridine-3-carbaldehyde

Beteiligte Stoffe

Reaktionsschritte

A mixture of 2-methoxy-5-cyanopyridine (61.26 g), semi-carbazide hydrochloride (76.4 g), sodium acetate (74.92 g), ethanol (1,300 ml) and water (400 ml) was hydrogenated at 344 kPa using Raney nickel catalyst (1.0 g). The mixture was evaporated to a volume of 500 ml, water (1,000 ml) was added and the mixture was allowed to stand at 0° overnight. The mixture was filtered and the solid was washed with water and dissolved in 10% hydrochloric acid (1,000 ml). Formaldehyde solution (36% w/v, 450 ml) was added and the mixture was warmed for 15 minutes, allowed to cool and was added to a solution of sodium acetate (298.5 g) in water (900 ml). This mixture was extracted with ether and the combined extracts were successively washed with aqueous potassium carbonate and water and were dried and evaporated to give 6-methoxypyridine-3-carboxaldehyde (31.5 g, 50%), m.p. 48-49°.

Herkunft & Nachweise