Jayavant D. Patil

[C16MPy]AlCl3Br: an efficient novel ionic liquid for synthesis of novel 1,2,4-triazolidine-3-thiones in water

An efficient novel ionic liquid, [C16MPy]AlCl3Br has been synthesized and explored as a catalyst for an eco-friendly synthesis of novel 1,2,4-triazolidine-3-thiones in water at ambient temperature. A variety of aldehydes undergo smooth reaction with thiosemicarbazide and substituted thiosemicarbazides. In the case of substituted thiosemicarbazides the corresponding 1,2,4-triazolidine-3-thiones are obtained as products instead of 1,3,4-oxadiazoles. A broad variety of functional groups are tolerated and a large number of substrates can be applied with this protocol. Rapid eco-friendly reactions with high yields, use of ambient temperature and water as a solvent, easy work-up procedure as well as isolation of product, excellent catalyst recyclability, high atom economy, novelty of ionic liquid as well as the protocol are the auxiliary advantages of the protocol.

Dicationic 1,3-Bis(1-methyl-1H-imidazol-3-ium) Propane Copper(I) Dibromate : Novel Heterogeneous Catalyst for 1,3-Dipolar Cycloaddition

Abstract We disclose synthesis of a novel dicationic 1,3-bis(1-methyl-1H-imidazol-3-ium) propane copper(I) dibromate [Bis-(MIM)](CuBr2)] and explored its potential as a heterogeneous catalyst in 1,3-dipolar cycloaddition for regioselective synthesis of 1, 4-disubstituted-1,2,3- triazoles in excellent yields in ethanol: water (60:40%) system at 80°C. The noteworthy feature of the protocol includes in situ generation of aryl azides by azotisation of aryl as well as alkyl halides with sodium azide thereby enduring facile 1,3-dipolar cycloaddition with terminal alkynes.Graphical Abstract

A polymer supported ascorbate functionalized task specific ionic liquid: an efficient reusable catalyst for 1,3-dipolar cycloaddition

A novel polymer supported ascorbate functionalized task specific ionic liquid was designed and synthesized. It has been demonstrated that the synthesized polymer supported ionic liquid acts as an efficient catalyst for regioselective Huisgen 1,3-dipolar cycloaddition of aryldiazonium tetrafluoroborate, sodium azide and terminal alkyne, which provide a series of 1,4-disubstituted-1,2,3-triazoles in high yields at room temperature as well as showing an aptitude for in situ incorporation of copper.

An efficient synthesis of anti-microbial 1,2,4-triazole-3-thiones promoted by acidic ionic liquid

Acidic ionic liquid, [(Py)2SO][HSO4]2 has been used as an efficient catalyst for the reaction of ketone with thiosemicarbazide in ethanol at room temperature for the eco-friendly synthesis of spiro-1,2,4-triazolidine-3-thiones. Smooth reactions, ambient temperature, use of alcohol as a solvent, high yields, easy work-up procedure and excellent recyclability of ionic liquid and high atom economy are the auxiliary advantages of the present protocol, which makes it ecofriendly. All the synthesized 1,2,4-trioazoles were screened for antimicrobial activity. Most of compounds displayed moderate to good biological activity.

Dual functionalized task specific ionic liquid promoted in situ generation of palladium nanoparticles in water: synergic catalytic system for Suzuki–Miyaura cross coupling

Herein we report the synthesis of a novel, dual functionalized task specific ionic liquid possessing cation with hydroxyl functionality which induces reaction in water and acts as a reducing agent as well as an anion with prolinate functionality serves as ligand and stabilizes and/or activates the in situ formed palladium nanoparticles (Pd-Nps) thus act as palladium(0) reservoirs. The generated palladium nanoparticles were characterized by UV-visible spectroscopy, high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED) and energy-dispersive X-ray spectroscopy (EDX) analysis. These in situ synthesized palladium nanoparticles with particle size between 3 to 9 nm exhibited a high catalytic activity in the Suzuki–Miyaura cross-coupling of aryl halide with aryl boronic acid without using external phosphine ligand. Less activated aryl chlorides also coupled smoothly with aryl boronic acid. It is noteworthy that, isolation of the products were performed by the simple extraction in diethyl ether, and the aqueous system containing ionic liquid along with Pd-NPs was recycled for seven times, without significant loss of catalytic activity.

Sulfamic Acid: A Mild, Efficient, and Cost-Effective Catalyst for Synthesis of Indoloquinoxalines at Ambient Temperature

Abstract A simple, cost-effective method for synthesis of indoloquinoxalines from isatin and o-phenylenediamine employing a catalytic amount of sulfamic acid at ambient temperature is reported. Moreover, the method is applicable for a variety of isatins, ninhydrin, 4-hydroxynaphthaquinone, and 1,2-diketones. The key features of the protocol include rapid reactions with good yields, simple workup procedure, and easy isolation of products. GRAPHICAL ABSTRACT

Novel task-specific ionic liquid for room temperature synthesis of spiro-1,2,4-triazolidine-3-thiones

An efficient, novel, task-specific ionic liquid, [2-hydroxymethylpyridinium butanesulfonic acid]HSO4 has been designed for the rapid synthesis of spiro-1,2,4-triazolidine-3-thiones from isatins and thiosemicarbazides in water as an universal solvent at room temperature. The hydroxymethyl functionality tethered to pyridinium nucleus facilitates the reaction in water. This is the first method proceeded at room temperature for synthesis of spiro-1,2,4-triazolidine-3-thiones. The novelty of the method is synthesis of novel task-specific ionic liquid, energy efficiency, atom economy, wide substrate scope, shorter reaction time, high yield of products, and use of water along with ionic liquid are greener aspects of present method.Graphical abstract

1,1′-Sulfinyldipyridinium bis (hydrogen sulfate) ionic liquid: synthesis and application in the temperature-influenced synthesis of novel pyranopyrimidinediones and pyranopyrimidinetriones

A novel and robust dication homo-anionic ionic liquid with the properties of a Bronsted acid is shown to efficiently catalyse the reaction of salicylaldehyde and 6-amino uracil in ethanol to produce novel pyranopyrimidinediones and pyranopyrimidinetriones under ambient and reflux conditions, respectively. The ionic liquid can be synthesized from inexpensive, commercially available precursors. A mechanism is suggested for these transformations. The advantages of this method include novelty in terms of the ionic liquid, together with a high efficiency, easy work-up procedure and purification, convenient operation, mild and environmentally benign reaction conditions.