An efficient and facile synthesis of new tetracyclic fused pyrazolo[4,3-c][1,2,4]triazino[4,5-a]quinolin-4(5H)-ones

The chemistry of 4-(dicyanomethylene)-3-methyl-l-phenyl-2-pyrazoline-5- ones as a privileged scaffold in synthesis of heterocycles

BACKGROUND

The reactivity of 4-(dicyanomethylene)-3-methyl-l-phenyl-2-pyrazoline-5-one DCNP 1 and its derivatives makes it valuable as a building block for the synthesis of heterocyclic compounds like pyrazolo-imidazoles, - thiazoles, spiropyridines, spiropyrroles, spiropyrans and others. As a number of publications have reported on the reactivity of DCNP and its derivatives, we compiled some features of this interesting molecule.

OBJECTIVE

This article aims to review the preparation of DCNP, its reactivity and application in heterocyclic and dyes synthesis.

CONCLUSION

In this review we have provided an overview of recent progress in the chemistry of DCNP and its significance in synthesis of various classes of heterocyclic compounds and dyes. The unique reactivity of DCNP offers unprecedentedly mild reaction conditions for the generation of versatile cynomethylene dyes from a wide range of precursors including amines, α-aminocarboxylic acids, their esters, phenols, malononitriles and azacrown ethers. We anticipate that more innovative transformations involving DCNP will continue to emerge in the near future.

Synthesis, characterization, and antimicrobial activity of some new N-aryl-N'-(2-oxoindolin-3-ylidene)-benzohydrazonamides

A green approach was developed for synthesizing a series of (isatin-3-ylidene)-hydrazonamides 3a-j from the reaction between isatin, (isatin-3-ylidene)malononitrile, or 2-cyano-2-(2-isatin-3-ylidene)acetate and benzohydrazonamide in ethyl acetate solutions at ambient temperature. The structures of the new compounds were confirmed on the basis of spectral data. In this eco-friendly medium, a variety of (isatin-3-ylidene)hydrazonamides were obtained free of catalyst in good to excellent yields. All the synthesized products were evaluated for their antimicrobial activity. Among the compounds tested, 3b and 3d exhibited good antibacterial activity against Staphylococcus aureus, whereas others responded moderately with reference to the standard drug ciprofloxacin.