1,3-Diethyl 2-oxopropanedioate → hydroxy [2-[4-(1H-imidazol-1-yl)-phenyl]-2-oxoethyl]propanedioic acid diethyl ester

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Reaction Steps

A mixture of diethylketomalonate (87.08 g, 0.50 mole) and 4-(imidazol-1-yl)acetophenone (93.1 g, 0.50 mole) is warmed to 95°-100° C. with stirring for three hours. During this time, the original tan slurry is transformed into a black syrup. At the end of three hours, anhydrous ethanol (130 ml) is added with stirring, resulting in a black solution. This solution is cooled to room temperature, an aliquot is removed and scratched to induce crystallization, and the crystals thus obtained returned to the cool solution. Upon standing overnight at 8° C., the solution forms a solid mass, which is suspended in absolute ethanol (100 ml) and filtered to obtain a brownish solid, which is dried at 43° in a vacuum oven for four hours to yield 67 g hydroxy [2-[4-(1H-imidazol-1-yl)-phenyl]-2-oxoethyl]propanedioic acid diethyl ester. Material thus obtained is suitable for use without additional purification, however, it can be recrystallized from methanol to give pure product, mp 155°-156° C.

Provenance & Evidence