Isatin In Water Research Articles

Unprecedented, catalyst‐free, and rapid one‐pot, three‐component green synthesis of substituted 3‐hydroxy‐2‐oxindoles in water

AbstractAn efficient, unprecedented, catalyst‐free, and rapid synthesis of substituted 3‐hydroxy‐2‐oxindoles is described by the one‐pot, three‐component reaction of hydrazine hydrate, ethyl acetoacetate, and isatins in water. The reported protocol is a green and general route for the simple preparation of new heteroaromatic substituted 3‐hydroxy‐2‐oxindoles in quantitative yields under very mild reaction conditions by using simple, cheap, and readily available materials. The developed method is effectively applicable to a variety of isatin substrates. Operational simplicity, mild and greener reaction conditions, short reaction time, a wide scope of substrates, good isolated yields of the products, and environmentally benign reaction medium are the distinctive features of the present method.

A Sulfonated Phenanthrolinum Salt of Phosphotungstate as Novel Catalyst for the Efficient Synthesis of 3,3′-Diaryloxindoles

A novel heteropolyanion-based Brønsted acidic ionic liquid (BAIL) material [PhBs]3PW12O40, butane mono sulfoacid-functionalized phenanthrolinum salt of phosphotungstate catalyst (PhBs-PW), was synthesized and characterized with FTIR, 1H and 13C NMR, Electro-Spray Ionization Mass Spectrometry (ESI-MS), EDX, FE-SEM, and TG analysis. The new prepared catalyst was used for the efficient synthesis of 3,3́́-diaryloxindole derivatives from the condensation of indole with isatins in water under reflux condition. The resultant condensation reaction using the introduced catalyst showed high yields of the products up to 97% and good recyclability of the catalyst confirmed in eight reusability runs.

Thermodynamics of Dissolution for Crystalline Racemic Tartaric and Glutaric Acids and Isatin in KOH Aqueous Solutions at 298.15 K

Enthalpies of dissolution are found for crystalline racemic tartaric and glutaric acids and isatin in water and in potassium hydroxide solutions at 298.15 K via direct calorimetry. The protolytic equilibria in isatin aqueous solutions are studied at 298.15 K and ionic strengths of 0.5 (relative to potassium nitrate) by potentiometric means. Standard enthalpies of formation are calculated for racemic tartaric and glutaric acids, isatin, and the products of their dissociation in aqueous solutions.

One-Pot, Catalyst-Free Synthesis of Spiro[dihydroquinoline-naphthofuranone] Compounds from Isatins in Water Triggered by Hydrogen Bonding Effects

A one-pot, catalyst-free route to spiro[dihydroquinoline-naphthofuranone] compounds from isatins through ring-opening and cyclization processes in water is disclosed. Hydrogen-bonding effects of water proved to be the key factor to accelerate the transformation. In addition, the chemistry provides several advantages including that it is free of organic solvents, a simple operation, and a gram-scale synthesis and uses inexpensive reagents and a recyclable reaction medium.

Nano MgBi2O4: A Novel Green Catalyst for the One-step Cascade Condensation of Arylamines, Acetone and Isatins in Water

Nano-size MgBi2O4 has been synthesized for the first time via a simple co-precipitation method using the surfactant N-cetyl- N,N,N-trimethylammonium bromide (CTAB). Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray powder diffraction (XRD) techniques were employed to characterize the nano-catalyst. Additionally, the reactivity of the prepared nanoparticles was investigated in the synthesis of 1\(^{\prime }\)-aryl-2\(^{\prime }\)-(2-oxoindolin-3-yl)spiro[indoline-3,5\(^{\prime }\)-pyrroline]-2,3\(^{\prime }\)-diones in a one-pot, one-step and pseudo four-component condensation of arylamine, acetone, and isatins at 50°C in water. Five new compounds were synthesized and identified. This procedure has various advantages such as, short reaction times, mild eco-friendly conditions and excellent yields to prepare a novel class of heteroaromatic compounds. MgBi2O4 possess superior qualities such as easy and economic preparation procedure and handling, stability, and non-toxicity. Its reusability has also been examined upto 4 runs without activity loss. Nano MgBi2O4 was synthesized for the first time via a simple co-precipitation method using the surfactant N-cetyl-N,N,N-trimethylammonium bromide (CTAB). The reactivity of the nanoparticles was investigated in the synthesis of 1 ′-aryl-2 ′-(2-oxoindolin-3-yl)spiro[indoline-3,5 ′-pyrroline]-2,3 ′-diones by the one-step, pseudo four-component condensation of arylamines, acetone and isatins at 50°C in water.

ChemInform Abstract: Organocatalyzed Direct Asymmetric Aldol Reaction of Isatins in Water: Low Catalyst Loading in Command.

AbstractA highly efficient diamine catalyst is developed which is used in low loadings in combination with 2,4‐dinitrophenol to catalyze the direct aldol reaction between isatin derivatives and ketones.

Catalyst-free alkylation of aminopyrazole by isatin in water

Reactions of isatins with 5-aminopyrazole afforded the 3-(5-aminopyrazol-4-yl)-3-hydroxy-2-oxindolines in good to excellent yields in refluxing water. No catalysts were required in the process. The new method exhibited the characteristics including green process, high yields, easy operation, and mild reaction conditions.

Organocatalyzed direct asymmetric aldol reaction of isatins in water: low catalyst loading in command

Simple primary–tertiary diamines easily derived from natural primary amino acids have been used to catalyze the aldol reactions in water. The 1 mol % of diamine catalyst is sufficient to catalyze the aldol reaction of cyclohexanone/acetone to isatins provided 3-substituted-3-hydroxy-2-oxindole in good yield and good enantioselectivity. The methodology highlights the importance of low catalyst loading in achieving high enantioselectivity.

ChemInform Abstract: A Facile One‐Pot Synthesis of Substituted Quinolines via New Multicomponent Reaction.

AbstractQuinoline derivatives (IV), (VI) are efficiently obtained in a one‐pot three‐component reaction of alkyl 4‐chloroacetate or ethyl chloropyruvate and activated acetylenic compounds in the presence of the nucleophilic form of isatin in water.

A Facile One‐Pot Synthesis of Substituted Quinolines via New Multicomponent Reaction

An efficient synthesis of quinoline derivatives is described via the reaction between ethyl chloropyruvate or alkyl 4‐chloroacetoacetate and activated acetylenic compounds in the presence of nucleophilic form of isatin in water as the solvent. Nucleophilic form of isatin is produced from the reaction of isatin and triethylamin.

ChemInform Abstract: First Synthesis of 2‐Tropolonylquinoline‐4‐carboxylic Acid Derivatives via Pfitzinger Reaction in Water.

A facile and clean synthesis of novel 2-tropolonyl substituted quinoline-4-carboxylic acids via Pfitzinger reaction of 3-acetyltropolone or 3-acetyl-5-bromotropolone with different isatins in water was described. It was the first time that the Pfitzinger reaction was applied to the troponoid field. The structures of all the synthesized compounds were characterized by elemental analysis and spectral data.

A highly efficient synthesis of oxindoles using a functionalized silica gel as support for indium(III) acetylacetonate catalyst in an aqueous-acetonitrile medium

Aminopropylsilica gel (APSG) was obtained by the modification of silica gel with 3-aminopropyltriethoxy silane. The indium(III) acetylacetonate complex was then subsequently anchored to yield In(acac) 3-bonded silica gel (In(acac) 3-APSG). The structure was investigated and confirmed by surface area (BET), elemental and thermogravimetric analyses, FT-IR, 13C-CPMAS spectral studies and inductively coupled plasma mass spectrometry technique (ICP-MS). The new In(acac) 3-APSG material was tested in the synthesis of oxindoles derivatives that were synthesized via the electrophilic substitution reaction of indoles with various isatins in water. The catalyst is highly stable and recyclable for several times. The work-up procedure is very simple and oxindoles were obtained in high yields.

Solvent Effect on the Kinetics of Ring Opening of Isatin in Water–Ethanol Mixtures

The kinetics of amide bond cleavage of isatin and N-methylisatin in the presence of ethanol was followed spectrophotometrically in the ranges of solvent composition (0-70%v/v) and temperature (40-60°C) using piperidine as a nucleophile. The reaction proceeds according to pseudo first-order kinetics. The rate of reaction strongly decreased with increasing organic solvent content. The thermodynamic activation parameters were calculated and discussed in terms of solvation. No linearity was observed between log (rate constant) and reciprocal dielectric constant for the solvent used, suggesting that there is selective solvation by the more polar water. The reactivity was analysed in the light of various simple and multiple regression equations using Kamlet–Taft solvatochromic parameters which were applied successfully to the mixed aqueous - ethanol mixtures. Finally, a mechanism for the ring opening is proposed

First Synthesis of 2-Tropolonylquinoline-4-carboxylic Acid Derivatives via Pfitzinger Reaction in Water

A facile and clean synthesis of novel 2-tropolonyl substituted quinoline-4-carboxylic acids via Pfitzinger reaction of 3-acetyltropolone or 3-acetyl-5-bromotropolone with different isatins in water was described. It was the first time that the Pfitzinger reaction was applied to the troponoid field. The structures of all the synthesized compounds were characterized by elemental analysis and spectral data.

Ultrasound-assisted three-component synthesis of 3-(5-amino-1 H-pyrazol-4-yl)-3-(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)indolin-2-ones in water

Indium(III) chloride was found to be an efficient catalyst for the synthesis of 3-(5-amino-1 H-pyrazol-4-yl)-3-(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)indolin-2-ones by one-pot, three-component reaction of dimedone, 1 H-pyrazol-5-amines and isatins in water under ultrasonic irradiation. The advantages of this method are the use of a readily available catalyst, easy workup, excellent yields, and the use of water as a solvent that is considered to be relatively environmentally benign.