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.