A Novel Method for the Synthesis of Spiro[indoline‐Pyrazolo[4′,3′:5,6]pyrido[2,3‐d]pyrimidine]triones by Alum as a Reusable Catalyst

Abstract

Synthesis of spiro[indoline‐pyrazolo[4′,3′:5,6]pyrido[2,3‐d]pyrimidine]trione derivatives by a cyclo‐condensation reaction of indolin‐2‐ones, barbituric acids, and 1,3‐diphenyl‐1H‐pyrazol‐5‐amines with the ionic liquid as an effective green reaction media and in the presence of Alum as a reusable catalyst was reported. Excellent yields of products, green media, use of a reusable catalyst, and short reaction time are the main advantages of this new method.

Synthesis of spiro-fused heterocyclic scaffolds through multicomponent reactions involving isatin

“…), up to 98:2 enantiomeric ratio (e.r.)). 100 A simple and efficient method for the synthesis of pyrazolopyridine based spirooxindoles was also reported by Kamal and co-workers where isatins, 5-phenyl-1H-pyrazol-3-amine and 1,3-dicarbonyl compounds react in the presence of sulfamic acid (H 2 NSO 3 H) as a green catalyst. 101 The three-component reactions of isatins 1, cyclic-1,3-diones 127, and pyrazol-5-amine 147 were successfully established and led to the formation of pyrazole-fused 1,4-dihydropyridine skeletons 148 using the heterogeneous aluminosilicate nanoparticle catalyst under eco-friendly conditions (Scheme 54).…”

Recent Developments in the MCRs Synthesis of Pyridopyrimidines and Spiro‐Pyridopyrimidines

“…Ionic liquids were also used for the sythesis of spiro‐pyridopyrimidines. Shirvan et al reported the synthesis of the spiro[indoline‐pyrazolo[4′,3′:5,6]pyrido[2,3‐d]pyrimidine]trione derivatives 112 by a cyclocondensation reaction of isatin, barbituric acids, and 1,3‐diphenyl‐1 H ‐pyrazol‐5‐amines using ionic liquid [bmim]PF 6 in the presence of Alum as a reusable catalyst at 100°C in high yields (83–98%) (Scheme ). Initially, they examined various catalysts such as Alum, SSA, SnCl 4 , p ‐TSA, and CAN.…”

A Quick, Simple and Clean Synthesis of Spiro(indoline‐3,4′‐pyrazolo[4′, 3′:5,6]pyrido[2, 3‐d]pyrimidines) in Water through a Novel One‐Pot Multicomponent Reaction

“…For such an effort several synthetic procedures have been reported. Classically, spiro[indoline‐3, 4′‐pyrazolo[4′, 3′:5,6]pyrido[2, 3‐ d ]pyrimidines] are synthesized by the condensation reaction of isatins, barbituric acids and 5‐aminopyrazoles using various catalysts like p ‐TSA, alum in [Bmin]PF 6 , organic‐inorganic hybrid material (SG@NH 2 @2AB−Sn), sulfamic acid and organo‐nanocatalyst (Fe 2 O 3 @SiO 2 @vitB 1 ) . In a newer method, Balamurugan et al .…”