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The reaction of 3-ethoxycarbonylcoumarin with derivatives of cyanoacetylhydrazine directly in the sample tube of the NMR spectrometer was investigated by 1H NMR spectroscopy. The structure of the components of the reaction mixtures was established, and their relative concentrations at the various stages of the reaction were estimated. The sequence of processes occurring in the reactions was analyzed. Both the general characteristics and the differences in the course of the reaction with cyanoacetylhydrazine or its N-isopropylidene derivative as second component were established. [ABSTRACT FROM AUTHOR]

Reaction between the N,N′-diisopropylidene and N,N′-diacetyl derivatives of malonic acid dihydrazide and 3-acyl(3-cyano, 3-ethoxycarbonyl)coumarins under the conditions of the Michael reaction lead to the formation of N′-isopropylidene and N′-acetyl derivatives of coumarin-3-carboxylic acid hydrazide. Ethoxycarbonylacethydrazide reacts in an analogous manner. Special features have been studied of the interaction of malonic acid amide derivatives with unsubstituted coumarin and with coumarins containing electron-withdrawing groupings in position 3 of the ring. [ABSTRACT FROM AUTHOR]

A stepwise sequence for the interaction of 3-ethoxycarbonyl(acyl)coumarins with cyanoacetylhydrazine, its N-acetyl and N-isopropylidene derivatives, leading to the formation of 3-cyanocoumarins, is proposed and demonstrated. It was established that the 3-cyanocoumarins formed are also able to participate in further conversions by a type of Michael reaction. [ABSTRACT FROM AUTHOR]