Garima Khanna

An efficient and confluent approach for the synthesis of novel 3,4-dihydro-2H-naphtho[2,3-e][1,3]oxazine-5,10-dione derivatives by a three component reaction in ionic liquid

A catalyst free multicomponent reaction (MCR) capable of affording a wide range of novel 3,4-dihydro-2H-naphtho[2,3-e][1,3]oxazine-5,10-dione derivatives via one pot three component condensation of 2-hydroxy-1,4-naphthoquinone, aromatic amine and formaldehyde in ionic liquid [bmim]BF4 is reported. Mild reaction conditions, high yields, short reaction time, and easy separation are some of the salient features of the present protocol.

Multicomponent Domino Process for the Synthesis of Some Novel Benzo[a]chromenophenazine Fused Ring Systems Using H2SO4, Phosphotungstic Acid, and [NMP]H2PO4

Abstract Efficient, mild, and quantitative procedures for the synthesis of functionalized benzo[c]chromeno[2,3-a]phenazine derivatives by one-pot, four-component condensation of 2-hydroxynaphthalene-1,4-dione, 1,2-phenylenediamines, aromatic aldehydes, and cyclic 1,3-dicarbonyl compounds have been developed using catalytic amounts of H2SO4 and phosphotungstic acid in EtOH/H2O (1:1) under reflux and also with [NMP]H2PO4, which acts as catalyst and medium at 80 °C. The reaction avoids tedious workup procedure due to the direct precipitation of products from the reaction medium. The present finding provides promising synthetic strategies for the synthesis of libraries with functional group diversity. GRAPHICAL ABSTRACT

Efficient catalyst-free synthesis of diversified bis (spirooxindoles) via one-pot, three-component reaction

ABSTRACT A catalyst-free, one-pot synthesis of bis-spirooxindoles has been carried out by a three-component reaction of bis-isatins, malononitrile, and various cyclic enolizable carbonyl compounds in ethylene glycol at 100 °C. The protocol provides an easy and simple route for the synthesis of such complex compounds, in short reaction times and high yields. No chromatographic techniques have been employed for the purification of the compounds. GRAPHICAL ABSTRACT

A Facile and Convenient Approach for the Synthesis of Novel Sesamol–Oxazine and Quinoline–Oxazine Hybrids

A series of functionalized sesamol–oxazine and quinoline–oxazine hybrids have been synthesized via one-pot reaction of sesamol/6-hydroxyquinoline, aromatic amines, and methanal. The structures of all the novel compounds were confirmed by spectral data. The structures of the synthesized hybrids were also confirmed by X-ray crystallographic studies. Mild reaction conditions, operational simplicity, short reaction times, simple workup, and high yields of products are salient features of this methodology.

Expedient Synthesis of Diverse Spirooxindoles via Multicomponent Approach in Presence of Green Catalyst

An efficient, convenient and environmentally benign procedure for the construction of various bioactive spirooxindoles has been developed by condensation reactions of isatins, malononitrile and α-methylene carbonyl compounds/enols in the presence of starch solution as expedient, eco-friendly and biodegradable catalyst at 60 °C. The prominent features of the above protocol are short reaction time, high atom economy, simple work-up, cost-effectiveness, avoidance of toxic chemicals.

Synthesis of Spiro[Indene-2,2′-Naphthalene]-4′-Carbonitriles and Spiro[Naphthalene-2,5′-Pyrimidine]-4-carbonitriles via One-pot Three Component Reaction Using Task Specific Ionic Liquid

A novel and efficient methodology has been developed for synthesizing indane-1,3-dione and pyrimidine based spirocyclic compounds. The synthesis has been achieved via multicomponent reaction of indane-1,3-dione/1.3-dimethylbarbituric acid, variously substituted aromatic aldehydes and cyclohexylidene malononitrile in presence of catalytic amount of TSIL [bmim]OH. Short reaction time, high yields and use of non-chromatographic purification techniques are some of the advantages of this methodology.

Metal-free synthesis of 1,2,3-triazoles by azide–aldehyde cycloaddition under ultrasonic irradiation in TSIL [DBU-Bu]OH and in hydrated IL Bu4NOH under heating

Efficient and environmentally benign procedures have been reported for the synthesis of 1,4-disubstituted 1,2,3-triazoles by reaction of aryl azides with aldehydes in task-specific basic ionic liquid [DBU-Bu]OH under ultrasonic irradiation and in hydrated ionic liquid tetrabutylammonium hydroxide (Bu4NOH) under conventional heating. These protocols represent simple, general, and efficient approaches in terms of good yields, operational simplicity, easy workup, and shorter reaction time for the synthesis of 1,4-disubstituted 1,2,3-triazoles under metal-free conditions.Graphical Abstract