Structural aspects of fullerene chemistry--a journey through fullerene chirality.

Our Biosphere comprises abundant biopolymers such as cellulose, chitin, and chitosan possessing highly desirable traits with biodegradability and renewability being prominent ones. The presence of ...

Biomass-Derived Renewable Carbonaceous Materials for Sustainable Chemical and Environmental Applications

l-Proline as an efficicent catalyst for the multi-component synthesis of 6-amino-4-alkyl/aryl-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles in water

Eco-friendly synthesis and biological evaluation of substituted pyrano[2,3-c]pyrazoles

Meglumine promoted one-pot, four-component synthesis of pyranopyrazole derivatives

Pyrano[2,3-c]pyrazoles are obtained via mixing ethyl acetoacetate, hydrazine hydrate, aldehydes or ketones and malononitrile in the absence of solvent. These same products were also obtained by reacting arylidenemalononitriles 3 with 3-methyl-2-pyrazolin-5-ones. NOE difference experiments confirmed that these products exist solely in the 2H form. Similar treatments of 3-amino-2-pyrazolin-5-one with arylidene-malononitrile afforded adduct 6. Similarly mixing ethyl cyanoacetate, hydrazine hydrate, aldehydes, with malononitrile gave the same product 6. A novel synthesis of 4-oxo-4H-pyrano[2,3-c]pyrazole (8) could be achieved via reacting 3-methyl-2-pyrazolin-5-one with a mixture of cyanoacetic acid and acetic anhydride. Similar treatment of 3-aminopyrazole 11 with the benzylidene-malononitrile produced the pyrazolo[2,3-a]pyrimidines 12a,b.

https://www.mdpi.com/1420-3049/15/9/6619/pdf

Green One Pot Solvent-Free Synthesis of Pyrano[2,3-c]-Pyrazoles and Pyrazolo[1,5-a]Pyrimidines

Studies with enaminones and enaminonitriles: synthesis of 3-aroyl and 3-heteroaroyl-pyrazolo-[1,5-a]pyrimidines

Depending on their nature, nitrile activated methylene compounds add readily to β-enaminones in presence of chitosan to yield dienamides, pyridones or pyridine thiones. The dienamides, formed in this manner, can be readily converted to pyridones by stirring in refluxing acetic acid. Reaction of pyridazinones with a mixture containing benzaldehyde, malononitrile and chitosan affords phthalazines that are also produced by reaction of pyridazinone with benzylidene-malononitrile.

/pdf/chitosan-as-an-eco-friendly-heterogeneous-catalyst-for-13rxf72r9z.pdf

Chitosan as an eco-friendly heterogeneous catalyst for Michael type addition reactions. A simple and efficient route to pyridones and phthalazines

Isolation and characterisation ofCs-symmetryC60Me5O2OH, the first methylatedfullerenol; a bis-epoxide with two oxygens in a pentagonal ring

Arylhydrazonomalononitriles 1a,b react with phenylhydrazine to yield amidrazones 2a,b that cyclize to give 2-aryl-5-phenylhydrazono-2,5-dihydro-[1,2,4]-triazine-6-carbonitriles 5a,b upon reaction with dimethylformamide dimethylacetal (DMFDMA). Refluxing 5a,b in glacial acetic acid resulted in the formation of the pyrazolo-1,2,4-triazines 6a,b. Compounds 6a,b were also formed upon treatment of 3-amino-4-phenylhydrazono-1-phenyl-2-pyrazolin-5-ones 7a,b with DMFDMA. Reacting these triazinyl arylhydrazononitriles 5a,b with hydroxylamine hydrochloride in ethanolic sodium acetate afforded amidrazones 8a,b that are readily cyclized in refluxing dimethylformamide into [1,2,4]triazino[1,2,3]triazines 10a,b.

Hamad M. Al-Matar

Papers

Green One Pot Solvent-Free Synthesis of Pyrano[2,3-c]-Pyrazoles and Pyrazolo[1,5-a]Pyrimidines

Studies with enaminones and enaminonitriles: synthesis of 3-aroyl and 3-heteroaroyl-pyrazolo-[1,5-a]pyrimidines

Chitosan as an eco-friendly heterogeneous catalyst for Michael type addition reactions. A simple and efficient route to pyridones and phthalazines

Isolation and characterisation ofCs-symmetryC60Me5O2OH, the first methylatedfullerenol; a bis-epoxide with two oxygens in a pentagonal ring

Efficient routes to pyrazolo[3,4-e][1,2,4]triazines and a new ring system: [1,2,4]triazino[5,6-d][1,2,3]triazines.