Facile one pot microwave enhanced multistep synthesis of novel biologically important scaffold spiro[indole-pyridopyrimidines]

Abstract

A rapid and efficient one pot method for the preparation of novel spiro [indole-pyrido[2,3-d]pyrimidines] by the reaction of 'insitu' generated spiro [indole-dihydropyridine] and urea / CS 2 using basic alumina as solid support/ or few drops of DMF as homogenizer under microwave irradiation is reported. Excellent yields (85-89%) and higher purity are obtained in mw enhanced one pot synthesis as compared to conventional procedure which required multistep processes using organic solvents and tedious workups.

More Sustainable Approaches for the Synthesis of N-Based Heterocycles

“…Recently, through the in situ formation of 3-(1-cyano-2-ethoxycarbonylethylidene)-2,3-dihydro-2-oxoindole by the Knoevenagel condensation of 1 H -indole-2,3-dione and ethyl cyanoacetate under microwave irradiation, indole based spiro derivatives were synthesized after reaction with 4-hydroxycoumarin through Michael addition . Spiro-[indole-pyrido[2,3- d ]pyrimidines] were reported, by the same authors, to be formed by the reaction of the in situ generated [indole-dihydropyridine] and urea/CS 2 under microwave irradiation using basic alumina as solid support and a few drops of DMF . Recently, spirooxindoles with fused chromenes were synthesized through the three-component condensation of isatin, malonitrile, and α-naphthol/β-naphthol using indium trichloride impregnated silica gel as a catalyst under microwave irradiation …”

“…640 Spiro-[indole-pyrido [2,3-d]pyrimidines] were reported, by the same authors, to be formed by the reaction of the in situ generated [indole-dihydropyridine] and urea/CS 2 under microwave irradiation using basic alumina as solid support and a few drops of DMF. 641 Recently, spirooxindoles with fused chromenes were synthesized through the three-component condensation of isatin, malonitrile, and R-naphthol/β-naphthol using indium trichloride impregnated silica gel as a catalyst under microwave irradiation. 642 ZrOCl 2 • 8H 2 O was tested as catalyst for the addition of indoles to R,β-unsaturated ketones under solvent-free conditions at 50 °C.…”

Efficient Protocol for Novel Hybrid Pyrimidines Synthesis: Antiproliferative Activity, DFT Analyses, and Molecular Docking Studies

“…In contrast, performing the same reaction in DMF afforded the product in 67% yield. This enhanced yield might be attributed to the unique properties of DMF (energy transfer solvent, high dielectric constant, and a homogenizer to elevate the temperature of the reaction) . In comparison to the solid-supported approach, the latter approach afforded the product in a relatively lower purity and yield.…”

“…This enhanced yield might be attributed to the unique properties of DMF (energy transfer solvent, high dielectric constant, and a homogenizer to elevate the temperature of the reaction). 24 In comparison to the solid-supported approach, the latter approach afforded the product in a relatively lower purity and yield. Therefore, a novel, cost-effective, convenient, and eco-friendly one-pot strategy for the synthesis of 4a,b is urgent.…”

Mesoporous silica nanoparticles (MSNs) as an efficient and reusable nanocatalyst for synthesis of β-amino ketones through one-pot three-component Mannich reactions

“…The products are formed in a single step and diversity can be achieved by simply varying a single component. 3,4 On the other hand, Mannich reaction is a very useful tool for development and synthesis of several molecules. 5 This reaction is an important carbon-carbon bond forming reaction in organic synthesis.…”