Diethyl oxalacetate sodium salt as a reagent to obtain functionalized spiro[indoline-3,4′-pyrano[2,3- c ]pyrazoles]

One-pot Synthesis of Pyrano[2,3-c]pyrazole Derivatives via Multicomponent Reactions (MCRs) and their Applications in Medicinal Chemistry

Background:

Many pyrano[2,3-c]pyrazole derivatives display diverse biological activities and some of them are known as anticancer, analgesic, anticonvulsant, antimicrobial, anti-inflammatory, and anti-malarial agents. In recent years, easy convergent, multicomponent reactions (MCRs) have been adopted to make highly functionalizedpyrano[2,3-c]pyrazole derivatives of biological interest. The synthesis of 1,4-dihydropyrano[2,3-c]pyrazole (1,4-DHPP, 2), 2,4-dihydropyrano[2,3-c]pyrazole (2,4-DHPP, 3), 4-hydroxypyrano[2,3-c]pyrazole (4-HPP, 4) derivatives, 1,4,4-substitied pyranopyrazole (SPP, 5) were reported via two-, three-, four- and five-component reactions (MCRs).

Methods:

This review article compiles the preparation of pyrano[2,3-c]pyrazole derivatives, and it highlights the applications of various pyrano[2,3-c]pyrazole derivatives in medicinal chemistry.

Results:

Varieties of pyrano[2,3-c]pyrazole derivatives were achieved via “One-pot” multicomponent reactions (MCRs). Different reaction conditions in the presence of a catalyst or without catalysts were adapted to prepare the pyrano[2,3-c]pyrazole derivatives.

Conclusion:

Biologically active pyrano[2,3-c]pyrazole derivatives were prepared and used in drug discovery research.

Engaging Isatins in Multicomponent Reactions (MCRs) - Easy Access to Structural Diversity

Multicomponent reactions (MCRs) are a valuable tool in diversity-oriented synthesis. Its application to privileged structures is gaining relevance in the fields of organic and medicinal chemistry. Isatin, due to its unique reactivity, can undergo different MCRs, affording multiple interesting scaffolds, namely oxindole-derivatives (including spirooxindoles, bis-oxindoles and 3,3-disubstituted oxindoles) and even, under certain conditions, ring-opening reactions occur that leads to other heterocyclic compounds. Over the past few years, new methodologies have been described for the application of this important and easily available starting material in MCRs. In this review, we explore these novelties, displaying them according to the structure of the final products obtained.

SLS-catalyzed Multi-component One-pot Reactions for the Convenient Synthesis of Spiro[indoline-3,4’-pyrano [2,3-c]pyrazole] Derivatives

Background,Objective: :

spiro[indoline-3,4′-pyrano[2,3-c]pyrazoles] derivatives are an important heterocyclic compounds. These compounds shows wide range of biological properties and exhibits varied pharmaceutical applications. Pyranopyrazoles, which are basically fused heterocyclic compounds and act as vasodilators, hypertensive, hypoglycaemic, and anticancer agents.

Methods:

An efficient and micelle-promoted surfactant catalyzed synthesis of spiro[indoline-3,4′-pyrano[2,3-c]pyrazoles] derivatives have been achieved via one-pot four-component reaction of hydrazine hydrate (phenyl hydrazine), ethyl acetoacetate, malononitrile (ethyl cyanoacetate) and isatin under thermal conditions (at 60°C) in water as a solvent.

Results:

Sodium lauryl sulphate (SLS) used has been found to be an efficient and green catalyst. The compounds reported during this work were obtained in excellent yield, in a short duration of time and ease of work up. They were purified by recrystalization from ethanol, and also the synthesized compounds were characterized by various spectroscopic techniques.

Conclusion:

The method offers several advantages such as safe, cost-effective and catalyst easily recovered and reused for a minimum of five cycles, that confirms its good stability. Short reaction times, high yield and usage of eco-friendly catalyst and solvent are the key features of this methodology.