5-Amino-2-hydroxy-2,4,6-cycloheptatrien-1-one → 2-(4-Hydroxy-5-oxo-1,3,6-cycloheptatrien-1-ylamino)-2-butenedioic Acid Diethyl Ester

Participants

Reaction Steps

A solution of diethyl acetylenedicarboxylate (183.5 g) and 5-amino-2-hydroxy-2,4,6-cycloheptatriene-1-one [147.5 g, described by T. Nozoe et al., Science Repts. Tokoku Univ., First ser., 35, 274(1952)] in ethanol (2,700 ml) is stirred at room temperature for 16 hours. The mixture is filtered and the precipitate is crystallized from ethanol to obtain crystals of the title compound, mp 108.5° C.

Provenance & Evidence