Background and Objective: Spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] 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]pyrazole] 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.