Green heterogeneous catalysis: chitosan and nanoparticulated magnesium oxide as ecofriendly catalyses for michael addition

Heterogeneous ecofriendly base catalysis namely, chitosan and naoparticulated MgO are promising new catalysis in Michael addition that can efficiency replace homogeneous polluting catalysts. Aminopyrancarbonitriles, pyranopyrazole, thiazologyridines and chromenes can be obtained in ethanolic or methanolic chitosan or MgO in good yields

Microwave mediated facile synthesis of some novel pyrazole, pyrazolo [1,5-a] pyrimidine and pyrazolo [5,1-c][1,2,4] triazin derivatives

4-Phenyl-2H-pyrazol-3ylamine 3 has been prepared by reaction of 2-phenyl-3-piperidine-1-yl-acrylonitrile [6] with hydrazine hydrate under microwave irradiation. Compound 3 reacted with acetylacetone and ethyl acetoacetate to yield pyrazolopyrimidine derivatives 7 and 8, respectively. Pyrazolopyrimidine derivative II can be formed by reaction of 3 with 2-ethoxymethylene-malononitrile. Compound 3 can be diazotized to yield the diazonium chloride and coupled with 6 to yield pyrazolotriazine derivative 25. Structures of the synthesized compounds were confirmed by their IR and NMR spectroscopic data