Solvent-Free Multicomponent Synthesis of N-Heterocycles | Chapter 10 | Recent Developments in Science and Technology for Sustainable Future

Synthetic medicinal chemists remain in the search of environmentally benign methods for the synthesis of biologically active molecules. However, green chemistry offers many fruitful synthetic protocols to do so but still development of newer methods with more advantages is the part of modern day’s synthetic research. Thus, the present chapter shows the synthetic efficiency of combination of two green chemical approaches for achieving a high degree of structural diversity with minimal efforts.

Author(s) Details:

Gulshan Singh,
Department of Chemistry, Sanatan Dharma College, Ambala Cantt-133001, Haryana, India.

Mohit Saini,
Department of Chemistry, Kurukshetra University, Kurukshetra, India.

Please see the link here: https://stm.bookpi.org/RDSTSF/article/view/13392

Application of Multicomponent Reactions for the Synthesis of Diverse Heterocyclic Scaffolds | Book Publisher International

In a one-pot approach, a combination of chemical reactions can be achieved by cascading two or more chemical transformations. The phrase is frequently applied to complicated goals (often natural products), with commercially available starting components. A sequential Knovenagel condensation/ Micheal addition is a popular, simple, and successful combination of reaction for the synthesis of a useful intermediate in the multistep complete synthesis of natural compounds. The most important is a combination of Diels-Alder cycloaddition and Sharpless Click Reaction, which produces complex polycycles and nitrogen-heterocycles as important scaffolds in the complex structure of natural products in a completely enantio, distereo, regio-specific, and selective manner. We have included a complete summary of several synthetic approaches used by chemists to produce heterocyclic rings utilising multicomponent strategies in the present book. The reader can easily locate the optimum approach for heterocycle synthesis thanks to a thorough text and detailed schematic representation of synthetic processes.

Author (s) Details

Anand Mohan Jha
Department of Chemistry, M.L.T. College, Saharsa, B. N. Mandal University Madhepura, Bihar, India.

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Determining the Synthesis of Pyrazoles via Multi-Component Reaction and Cyclization Cascade of Hydrazono Ugi Adducts | Chapter 12 | Challenges and Advances in Chemical Science Vol. 6

 In organic synthesis, multicomponent reactions (MCR) and cascade reactions are frequently used. Different substituted pyrazoles are accessed using these two synthetic methods. In the first section, we're interested in learning how to make aminocyanopyrazoles using a multicomponent process. The current study outlines a useful protocol for multicomponent reactions (MCRs) involving malononitrile, an orthoester, and hydrazine derivatives, all of which take place in the presence of an acid catalyst. The manufacture, isolation, and characterisation of a series of aminocyanopyrazoles 4 were indeed carried out. Such pyrazoles reacted with sodium nitrite, secondary amine reagent, and formic acidpyrazolotriazines 6 and pyrazolopyrimidinones 7 after being exposed to sodium nitrite. Sulfamoyl chloride was used to convert some of the aminopyrazoles into the corresponding sulfamides. The human (h) hCA I, II, IX, and XII isoforms of carbonic anhydrase (CA, EC 4.2.1.1) were tested as inhibitors of four carbonic anhydrase (CA, EC 4.2.1.1) isoforms. As a result, many of them revealed that these enzymes were inhibited at low micromolar or submicromolar concentrations. Low nanomolar CA inhibitors were found in the matching sulfamides. Acidic hydrolysis of Ugi adducts generated from -hydrazonocarboxylic acids and amino acetaldehyde dimethyl acetal leads to fragmentation of aminoacetaldehyde residues and the synthesis of pyrazoles in the second section. The essential phase of the cascade is proposed to be an aldol-type reaction of the hydrazone. MCR multicomponent reactions and Ugi cascade synthesis are efficient and interesting methods for obtaining good to moderate yields of pyrazoles.

Author(S) Details

Fatma Allouche
Laboratory of Medicinal and Environmental Chemistry, Superior Institute of Biotechnology of Sfax, University of Sfax, 3018, Sfax, Tunisia.

View Book:- https://stm.bookpi.org/CACS-V6/article/view/4612