Arup Kumar Dutta

Synthesis of dibenzoxanthene and acridine derivatives catalyzed by 1,3-disulfonic acid imidazolium carboxylate ionic liquids

New members of 1,3-disulfonic acid imidazolium carboxylate ionic liquids [DSIM][X] (where X = [CH3COO]−, [CCl3COO]−, [CF3COO]−) were prepared and characterized by 1H NMR,13C NMR, FT-IR, TGA,UV-vis and elemental analysis. The more acidic ILs [DISM][CCl3COO] and [DSIM][CF3COO] were efficiently utilized as recyclable catalysts for the preparation of 14H-dibenzo[a,j]xanthene and 1,8-dioxo-decahydroacridine derivatives in short times under solvent-free conditions at 80–100 °C with excellent yields. The above two ILs could be effectively utilized as catalysts for the synthesis of 1,8-dioxo-decahydroacridine in water at the same temperature.

Synthesis of anti-2,3-dihydro-1,2,3-trisubstituted-1H-naphth [1,2-e][1,3]oxazine derivatives via multicomponent approach

A series of anti-2,3-dihydro-1,2,3-trisubstituted-1H-naphth [1,2-e][1,3]oxazine derivatives 6 were exclusively obtained in high yields for the first time through multicomponent reactions (MCRs) of 2-naphthol, aromatic aldehydes and electron rich primary amines in ethanol at room temperature using CCl3COOH as catalyst. The same reaction could be conducted effectively in solvent-free medium at 100 °C. The stereochemistry of the two hydrogens connected to C-2 and C-4 (1,3) positions of the oxazine ring are identified as anti-orientation by single crystal XRD, COSY and NOESY analysis.

Dual nature of polyethylene glycol under microwave irradiation for the clean synthesis of oximes

Polyethylene glycol (PEG-400 and PEG-600) is an efficient, inexpensive, and recyclable homogeneous medium and catalyst (dual nature) for the clean synthesis of oximes (and aldoximes) under microwave irradiation in the absence of acid and base catalysts. Both aliphatic and aromatic aldehydes/ketones give satisfactory results under microwave irradiation within a short time.Graphical abstract

Design and Exploration of –SO3H Group Functionalized Brønsted Acidic Ionic Liquids (BAILs) as Task-Specific Catalytic Systems for Organic Reactions: A Review of Literature

For several decades various chemical industries are involved in environment pollution by using hazardous chemicals or excessive use of solvents or catalysts to get maximum amount of desired product. In this case acidic ionic liquids may act as safer substitute of volatile organic solvents/or traditional Brønsted or Lewis acid catalysts with their unique dual task-specific solvent-catalyst properties. Recent surge in the literature review clearly describes the importance, properties and applications of acidic ionic liquids as solvent and efficient reusable catalyst in organic reactions. This review presents an account of some recent reports indicating the synthesis and uses of –SO3H functionalized ionic liquids(SFILs) as catalyst in organic synthesis.

Studies on Structural Changes and Catalytic Activity of Y-zeolite Composites of 1,3-disulfoimidazolium trifluoroacetate Ionic Liquid (IL) for Three Component Synthesis of 3,4-dihydropyrimidinones

This report describes the development of six acidic composites of Y-zeolite with 1,3-disulfoimidazolium trifluoroacetate [Dsim][CF3COO] ionic liquid (IL) and displays the gradual increase of acidic IL mediated dealumination within zeolite framework with increasing loading in Powder XRD and IR studies. The structural changes of modified framework of zeolite were analyzed by SEM-EDX, TEM, TGA, BET and UV–Vis techniques. Out of the six composites, the more acidic [Dsim][CF3COO]/NaY = 20% (e) composite was evaluated as heterogeneous catalyst for multicomponent synthesis of 3,4-dihydropyrimidinones (DHPMs) under neat condition at various temperature.Graphical Abstract

Modelling of reference electrode for a SÌ3N4 gate pH ISFET

Ion sensitive field effect transistor (ISFET), which is a modification of metal oxide semiconductor field effect transistor, is a successor of the glass pH electrode. Since its inception over the four decades and beyond, it has witnessed a growing demand in various fields such as medical, food safety, military, waste water management etc. Proper positioning of the reference electrode in an ISFET device is very essential for the pH measurement process. In this work, a model for proper positioning of reference electrode with respect to the SÌ3N4 sensing surface of an ion sensitive field effect transistor has been developed. The model has been simulated in MATLAB simulation environment. The simulation results show that obtaining unambiguous reading is possible only when the reference electrode is placed more than the three times of the debye length of the electrolyte solution. This also gives an idea about the overall size of the measurement system.