Diethyl 2-(ethoxymethylidene)-3-oxobutanedioate → Triethyl 1,6-dihydro-6-oxo-2,3,5-pyridinetricarboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of ethylmalonamate (23.6 g, 0.18 mol) in absolute ethanol (300 mL) is added to a stirred solution of diethyl ethoxymethyleneoxalacetate (44.0 g, 0.18 mol) in ethanol (200 mL) at 0° C., followed by the addition, of solid sodium acetate (14.72 g, 0.18 mol). After stirring for ten minutes at 0° C., the mixture is heated to reflux and stirred for 13.5 hours. After cooling, the ethanol is removed under vacuum, and the residue diluted with water and acidified to pH 2 with concentrated hydrochloric acid. The aqueous solution is extracted with methylene chloride (2×200 mL) and the organic layer washed with 300 mL saturated sodium chloride, then dried over anhydrous magnesium sulfate and concentrated in vacuum to give 45.0 g of the title product as an orange oil.

Herkunft & Nachweise