Urea → 5-Carbethoxyuracil

Participants

Reaction Conditions

Reaction Steps

Urea (12 g, 200 mmol) was added to EtOH (300 mL) containing NaOC2H5 previously prepared from sodium (5.52 g, 240 mmol, 1.2 eq). Diethyl 2-(ethoxymethylene)malonate (43.2 g, 200 mmol, 1.0 eq) was added and the solution was stirred at 20° C. for 24 h, and then stirred at 90° C. for 24 h. The alcohol was removed by reduced pressure distillation. Ice-water (100 mL) was added to dissolve the residue. The product was precipitated by adding cold dilute hydrochloric acid. The solid was filtered off to afford ethyl 2,4-dioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate (8.5 g, 23%), which was used in next step without further purification.

Provenance & Evidence