Decyclization of Substituted 2-[2-Oxofuran-3(2 H )-ylidene)furan-2-carbohydrazides by the Action of Alcohols and Analgesic Activity of the Obtained Compounds

A new series of substituted 4-oxo-2-[2-(furan-2-ylcarbonyl)hydrazinylidene]butanoic acids and 2-[2-oxofuran-3(2 H )-ylidene]furan-2-carbohydrazides was synthesized. A methodology was developed for their decyclization under the action of primary and secondary alcohols with the formation of substituted alkyl 4-oxo-2-[2-(furan-2-ylcarbonyl)hydrazinylidene]butanoates, which exist in the form of three isomeric forms. Among the synthesized compounds, substances with pronounced analgesic activity were found.