Sodium ascorbate as an expedient catalyst for green synthesis of polysubstituted 5-aminopyrazole-4-carbonitriles and 6-amino-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles

Applications of pyrazolone in multicomponent reactions for the synthesis of dihydropyrano[2,3-c]pyrazoles and spiro-pyrano[2,3-c]pyrazoles in an aqueous medium

“…The methodology displays several advantages like-use of readily available reactants, operational simplicity, easy isolation of product, green reaction media, use of inexpensive and non-toxic catalyst, eco-friendly protocol, etc (Scheme 61). 112 The reaction mechanism for this transformation begins with the initial formation of pyrazolone from the reaction of hydrazine hydrate and ethyl acetoacetate that can then undergoes Michael addition with the in situ generated arylidene malononitrile from the Knoevenagel condensation reaction of aldehydes with malononitrile under the influence of sodium benzoate. In the final step, an intramolecular cyclization followed by tautomerization afforded the desired product.…”

Core‐shell structured magnetite silica‐supported hexatungstate: A novel and powerful nanocatalyst for the synthesis of biologically active pyrazole derivatives

“…Then, this anion is condensed with the W-S C H E M E 2 Proposed mechanism for the synthesis of 5-amino-1,3-diphenyl-1H-pyrazole-4-carbonitrile derivatives using Fe 4 F e 3 O 4 @CQDs@Si (CH 2 ) 3 NH 2 @CC@EDA@Cu Solvent-free, r.t. ). [70,71] Finally, the catalytic performance of our designed catalyst was compared with some of the catalysts recently used in the preparation of pyrazoles. This study showed that present catalyst is better than of the previous catalysts in recycling times and reaction time.…”

Two different facile and efficient approaches for the synthesis of various N-arylacetamides via N-acetylation of arylamines and straightforward one-pot reductive acetylation of nitroarenes promoted by recyclable CuFe2O4 nanoparticles in water

“…So, designing new protocols for the synthesis of amides via straightforward one-pot reductive acetylation of aromatic nitro compounds without isolation of the arylamine intermediates is very interesting. In this regard, it should be noted that one-pot multicomponent reactions (MCRs) are remarkable instruments for versatile preparation of a wide diversity of organic compounds especially biologic active molecules which have advantages such as high atom economy, escape of time-consuming protection-deprotection steps, and environmentally friendliness, making them absolutely better than classical multistep synthetic pathways [27][28][29][30][31][32][33][34][35][36][37].…”