Organic Synthesis

The present investigations entitled“Studies on the development of newer methodology for the synthesis of imidazoles and benzimidazoles under environmentally benign condition” was carried out under the supervision of Dr. Swapan Majumdar, Associate Professor, Department of Chemistry, Tripura University, Suryamaninagar-799022.
In modern organic synthesis, development of a clean technology for environmentally benign methodology for academia as well as the industry is a great challenge. Thus, the main objective of the present work is to introduce clean, simple, mild and eco-friendly methodology for the synthesis of some biologically and pharmacologically active heterocycles through exploration of new, cheap and commercially available reagents.
This

In the Part I of this proposed thesis, literature reviews on different environmentally benign protocols adopted in organic synthesis will be reported.
Part II of the proposed thesis will describe Amberlite IR 120 as solid supported catalyst, multicomponent approach for convenient synthesis of tri and tetra substituted imidazoles. This part will be sub-divided by two chapters. In Chapter 1, the synthesis of tri substituted imidazoles by the catalysis of Amberlite IR 120H+ will be discussed whereas synthesis of tetra substituted imidazoles will be discussed in Chapter 2.
In the Part III of the proposed thesis, Protic ionic liquid catalyzed substrate tuned green synthesis of 1,2-disubstituted and 2-substituted benzimidazoles with outstanding selectivity using Grindstone chemistry under solvent free condition will be described.
Part IV of the thesis will describe about the cleavage of acetals and ketals through the activation of 1, 3-dioxolane by protic ionic liquid in aqueous media with extraordinary selectivity and tolerance of many functional groups. This novel method was adopted for the preparation of some starting materials required for the synthesis of imidazoles and benzimidazoles described in Part II and Part

The most important part of our efforts towards the synthesis of environmentally benign protocols is the replacement of organic solvents by less toxic and safer green solvents like ionic liquids, water and also solvent-free conditions. Among this, water has been found to be very efficient due to its non-toxic character, enormous abundance, cheap and ready accessibility and thus used in many organic reactions through replacement of toxic, volatile and hazardous organic solvents. Biocatalysis is one of the most emerging tools for green chemistry and is the naturally occurring environmentally benign catalysts. Biocatalysed reactions have several advantages such as very fast reactions with excellent chemo-, regio- and stereoselectivities which are extremely difficult to achieve by conventional chemical methods and thus eliminate protection and deprotection strategy of functional groups required in traditional non bio synthesis, occurrence of reaction in aqueous media, tolerance of wide range of organic solvents, elimination of multiple steps and reduction of waste and hazards. Grindstone chemistry and ball milling process – these two approach are an efficient and environmentally friendly mechano-chemical synthetic approach for solvent-free synthesis. In this process reactions are performed by applying mechanical force such as