A General Method for the Synthesis of 11H-indeno[1,2-b]quinoxalin-11-ones and 6H-indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one Derivatives using Mandelic Acid as an Efficient Organo-catalyst at Room Temperature

2021 ◽  
Vol 08 ◽  
Author(s):  
Aditi Sharma ◽  
Gurpreet Kaur ◽  
Diksha Singh ◽  
Vivek Kumar Gupta ◽  
Bubun Banerjee
Keyword(s):  
Mandelic Acid ◽  
Room Temperature ◽  
Aqueous Ethanol ◽  
Low Cost ◽  
Catalytic Amount ◽  
Reaction Conditions ◽  
Metal Free ◽  
Naturally Occurring ◽  
Column Chromatographic ◽  
General Method

Aims: Synthesis of 11H-indeno[1,2-b]quinoxalin-11-ones as well as 6H-indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one derivatives under greener conditions. Background: Quinoxaline and related skeletons are very common in naturally occurring bioactive compounds. Objective: Design a facile, green and organo-catalyzed method for the synthesis of 11H-indeno[1,2-b]quinoxalin-11-ones as well as 6H-indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one derivatives. Methods: Both the scaffolds were synthesized via the condensation of ninhydrin and o-phenylenediamines or pyridine-2,3-diamines respectively by using a catalytic amount of mandelic acid as an efficient, commercially available, low cost, organo-catalyst in aqueous ethanol at room temperature. Results: Mild reaction conditions, use of metal-free organocatalyst, non-toxic solvent, ambient temperature, and no column chromatographic separation are some of the notable advantages of our developed protocol. Conclusion: In conclusion, we have developed a simple, mild, facile and efficient method for the synthesis of structurally diverse 11H-indeno[1,2-b]quinoxalin-11-one derivatives via the condensation reactions of ninhydrin and various substituted benzene-1,2-diamines using a catalytic amount of mandelic acid as a commercially available metal-free organo-catalyst in aqueous ethanol at room temperature. Under the same optimized reaction conditions, synthesis of 6H-indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one derivatives was also accomplished with excellent yields by using pyridine-2,3-diamines instead of o-phenylenediamine.

A General Method for the Synthesis of 3,3-bis(indol-3-yl)indolin-2-ones, bis(indol-3-yl)(aryl)methanes and tris(indol-3-yl)methanes Using Naturally Occurring Mandelic Acid as an Efficient Organo-catalyst in Aqueous Ethanol at Room Temperature

2020 ◽  
Vol 7 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Arvind Singh ◽  
Gurpreet Kaur ◽  
Amninder Kaur ◽  
Vivek K. Gupta ◽  
Bubun Banerjee
Keyword(s):  
Mandelic Acid ◽  
Room Temperature ◽  
Aqueous Ethanol ◽  
Low Cost ◽  
Catalytic Amount ◽  
Environmentally Benign ◽  
Efficient Synthesis ◽  
Naturally Occurring ◽  
General Method

A simple, facile, straightforward and environmentally benign protocol has been developed for the efficient synthesis of pharmaceutically interesting 3,3-bis(indol-3-yl)indolin-2-ones, bis(indol- 3-yl)(aryl)methanes and tris(indol-3-yl)methanes using a catalytic amount of mandelic acid as an efficient, naturally occurring, low-cost, commercially available organo-catalyst in aqueous ethanol at room temperature.

Mandelic acid: An efficient organo-catalyst for the synthesis of 3-substituted- 3-hydroxy-indolin-2-ones and related derivatives in aqueous ethanol at room temperature

2020 ◽  
Vol 07 ◽  
Author(s):  
Gurpreet Kaur ◽  
Rajat Kumar ◽  
Shivam Saroch ◽  
Vivek Kumar Gupta ◽  
Bubun Banerjee
Keyword(s):  
Mandelic Acid ◽  
Room Temperature ◽  
Aqueous Ethanol ◽  
Catalytic Amount ◽  
Environmentally Benign ◽  
Scale Production ◽  
Indole Derivatives ◽  
Atom Economy ◽  
Reaction Conditions ◽  
Naturally Occurring

Background: Indoles and various indolyl derivates are very common in naturally occurring biological active compounds. Many methods are being developed for the synthesis of various bioactive indole derivatives. Objective: Synthesis of biologically promising structurally diverse indole derivatives under mild and environmentally benign conditions. Methods: Synthesis of 3-hydroxy-3-(5-(trifluoromethoxy)-1H-indol-3-yl)indolin-2-one was achieved by the reaction of equimolar mixture of isatin and 3-(trifluoromethoxy)-1H-indol using 20 mol% of mandelic acid as catalyst in aqueous ethanol at room temperature. Under the same optimized reaction conditions, synthesis of 3-(3-hydroxy-2-oxoindolin-3- yl)chroman-2,4-diones was accomplished via the reactions of substituted isatins and 4-hydroxycoumarin. On the other hand, 2-hydroxy-2-(indol-3-yl)-indene-1,3-diones and 10-hydroxy-10-(5-methoxy-1H-indol-3-yl)phenanthren-9(10H)-one were synthesized from the reactions of indoles and ninhydrin or 9,10-phenanthrenequinone respectively using the same 20 mol% of mandelic acid as an efficient organo-catalyst in aqueous ethanol at room temperature. Results: Mild, safe and clean reaction profiles, energy efficiency, high atom-economy, use of naturally occurring nontoxic organo-catalyst, easy isolation procedure by avoiding column chromatographic purification and gram scale production are some the major advantages of this developed protocol. Conclusion: A simple, straightforward and eco-friendly protocol has been developed for the efficient synthesis of biologically promising novel 3-hydroxy-3-(5-(trifluoromethoxy)-1H-indol-3-yl)indolin-2-one, 3-(3-hydroxy-2- oxoindolin-3-yl)chroman-2,4-diones, 2-hydroxy-2-(indol-3-yl)-indene-1,3-diones and 10-hydroxy-10-(5-methoxy-1Hindol-3-yl)phenanthren-9(10H)-one using a catalytic amount of mandelic acid in aqueous ethanol at room temperature.

Naturally Occurring Organic Acid-catalyzed Facile Diastereoselective Synthesis of Biologically Active (E)-3-(arylimino)indolin-2-one Derivatives in Water at Room Temperature

2019 ◽  
Vol 23 (16) ◽  
pp. 1778-1788 ◽  
Author(s):  
Gurpreet Kaur ◽  
Arvind Singh ◽  
Kiran Bala ◽  
Mamta Devi ◽  
Anjana Kumari ◽  
...  
Keyword(s):  
Room Temperature ◽  
Biologically Active ◽  
Environmentally Benign ◽  
Diastereoselective Synthesis ◽  
Substituted Anilines ◽  
Reaction Conditions ◽  
Naturally Occurring ◽  
Acid Catalyzed ◽  
Reaction Media ◽  
Column Chromatographic

A simple, straightforward and efficient method has been developed for the synthesis of (E)-3-(arylimino)indolin-2-one derivatives and (E)-2-((4-methoxyphenyl)imino)- acenaphthylen-1(2H)-one. The synthesis of these biologically-significant scaffolds was achieved from the reactions of various substituted anilines and isatins or acenaphthaquinone, respectively, using commercially available, environmentally benign and naturally occurring organic acids such as mandelic acid or itaconic acid as catalyst in aqueous medium at room temperature. Mild reaction conditions, energy efficiency, good to excellent yields, environmentally benign conditions, easy isolation of products, no need of column chromatographic separation and the reusability of reaction media are some of the significant features of the present protocol.

An efficient multicomponent, one-pot synthesis of Betti bases catalyzed by cerium (IV) ammonium nitrate (CAN) at ambient temperature

2016 ◽  
Vol 5 (4) ◽  
Author(s):  
Ramadan Ahmed Mekheimer ◽  
Abdullah Mohamed Asiri ◽  
Afaf Mohamed Abdel Hameed ◽  
Reham R. Awed ◽  
Kamal Usef Sadek
Keyword(s):  
Ambient Temperature ◽  
Environmental Pollution ◽  
Ammonium Nitrate ◽  
Room Temperature ◽  
Catalytic Amount ◽  
High Yield ◽  
Reaction Conditions ◽  
One Pot ◽  
Work Up ◽  
Cerium Iv Ammonium Nitrate

AbstractStarting from readily available 2-naphthol, aldehydes, aryl and alkylamines, a variety of Betti bases were efficiently synthesized utilizing a catalytic amount of cerium (IV) ammonium nitrate (CAN) at room temperature. This protocol has advantages of high yield, mild reaction conditions, no environmental pollution, diversity of reactants and simple work up procedure.

scholarly journals Morpholin-2-one Derivatives via Intramolecular Acid-Catalyzed Hydroamination

Synthesis ◽  
2019 ◽  
Vol 51 (07) ◽  
pp. 1643-1648 ◽  
Author(s):  
David Knight ◽  
Thomas Wirth ◽  
Abdul Hadi Aldmairi
Keyword(s):  
Amino Acids ◽  
Catalytic Amount ◽  
Practical Method ◽  
Trifluoromethanesulfonic Acid ◽  
Reaction Conditions ◽  
Available N ◽  
Metal Free ◽  
Acid Catalyzed

Substituted morpholin-2-one derivatives were readily obtained in two steps starting from commercially available N-protected amino acids. In a metal-free and practical method, a catalytic amount of trifluoromethanesulfonic acid was sufficient to generate morpholinones under mild reaction conditions in an intramolecular hydroamination reaction in good to excellent yields.

Synthesis of 2,4,5-trisubstituted imidazoles catalyzed by [Hmim]HSO4 as a powerful Brönsted acidic ionic liquid

2008 ◽  
Vol 86 (3) ◽  
pp. 264-269 ◽  
Author(s):  
Ahmad R Khosropour
Keyword(s):  
Ionic Liquid ◽  
Room Temperature ◽  
Low Cost ◽  
Catalytic Amount ◽  
Room Temperature Ionic Liquid ◽  
Acidic Ionic Liquid ◽  
Brønsted Acidic Ionic Liquid ◽  
Green Procedure

An efficient and green procedure for the synthesis of 2,4,5-trisubstituted imidazoles with various aldehydes using a catalytic amount of 1-methylimidazolium hydrogenesulfate as an active and low cost Brönsted acidic room temperature ionic liquid has been developed. The ionic liquid was easily separated from the reaction mixture and was recycled five times without any loss in activity.Key words: ionic liquid, 2,4,5-trisubstituted imidazoles, [Hmim]HSO4, aldehyde, benzil.

Facile and direct synthesis of symmetrical acid anhydrides using a newly prepared powerful and efficient mixed reagent

2015 ◽  
Vol 69 (3) ◽  
Author(s):  
Hamed Rouhi-Saadabad ◽  
Batool Akhlaghinia
Keyword(s):  
Carboxylic Acids ◽  
Room Temperature ◽  
Low Cost ◽  
Direct Synthesis ◽  
Reaction Conditions ◽  
Experimental Procedure ◽  
Short Reaction Time ◽  
Acid Anhydrides ◽  
Work Up ◽  
Trichloroisocyanuric Acid

AbstractAn efficient mixed reagent for direct synthesis of symmetrical carboxylic anhydrides from carboxylic acids has been prepared. Carboxylic acids are converted to anhydrides using triphenylphosphine/ trichloroisocyanuric acid under mild reaction conditions at room temperature. Short reaction time, excellent yields of products, low cost, availability of reagents, simple experimental procedure, and easy work-up of the products are the main advantages of the presented method.

DABCO Promoted Regioselective Synthesis of New Diversely Functionalized 3-Hydroxy-2-Oxindole Scaffolds

2014 ◽  
Vol 67 (5) ◽  
pp. 768 ◽  
Author(s):  
Pramod B. Thakur ◽  
Jagdeesh B. Nanubolu ◽  
Harshadas M. Meshram
Keyword(s):  
Catalytic Amount ◽  
Regioselective Synthesis ◽  
Reaction Conditions ◽  
Metal Free ◽  
Structural Framework

An efficient and highly regioselective γ-addition of β-keto sulfones on isatins has been achieved in the presence of a catalytic amount of 1,4-diazabicyclo[2.2.2]octane (DABCO) to afford a γ-(3-hydroxy-2-oxindole)-β-keto sulfone structural framework. The scope of the method is tested by screening a series of isatin electrophiles as well as β-keto sulfones. The described method was found to be very handy and provides straightforward access for the diversely functionalized 3-β-keto sulfone substituted-3-hydroxy-2-oxindole structural scaffolds in very good yields from readily available starting materials under metal-free reaction conditions.

Metal-Free Halogenation of N-Substituted Enaminoesters and Enaminones: A Facile Access to Functionalized α,α-Dihaloimines

Synthesis ◽  
2020 ◽  
Vol 52 (08) ◽  
pp. 1301-1314 ◽  
Author(s):  
Changfu Qiu ◽  
Heshui Yu ◽  
Chuanjiang Qiu ◽  
Fangyi Li ◽  
Tongchuan Suo ◽  
...  
Keyword(s):  
Transition Metals ◽  
Building Blocks ◽  
Synthetic Method ◽  
Safe Operation ◽  
Reaction Conditions ◽  
Metal Free ◽  
Synthetic Utility ◽  
General Method

An efficient and general method for the synthesis of functionalized α,α-dihaloimines via halogenation of N-substituted enaminoesters and enaminones is described. This reaction, in which both α,α-dihaloimines and mixed α,α-dihaloimines could be achieved in good to excellent yields, is believed to proceed via an α-monohalogenated enamine intermediate. This synthetic method features no use of transition metals, readily accessible substrates, mild reaction conditions, simple and safe operation, and gram scale synthesis. Furthermore, the synthetic utility of the products was demonstrated by their efficient transformations to further useful nitrogen-containing heterocycles and building blocks.

scholarly journals One-Pot, Metal-Free Synthesis of Dimethyl Carbonate from CO2 at Room Temperature

2020 ◽  
Vol 1 (3) ◽  
pp. 298-314
Author(s):  
Santosh Govind Khokarale ◽  
Thai Q. Bui ◽  
Jyri-Pekka Mikkola
Keyword(s):  
Ionic Liquid ◽  
Room Temperature ◽  
Dimethyl Carbonate ◽  
High Selectivity ◽  
Chemical Species ◽  
Side Reactions ◽  
Ambient Conditions ◽  
Reaction Conditions ◽  
One Pot ◽  
Metal Free

Herein, we report on the metal-free, one-pot synthesis of industrially important dimethyl carbonate (DMC) from molecular CO2 under ambient conditions. In this process, initially the CO2 was chemisorbed through the formation of a switchable ionic liquid (SIL), [DBUH] [CH3CO3], by the interaction of CO2 with an equivalent mixture of organic superbase 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) and methanol. The obtained SIL further reacted with methyl iodide (CH3I) to form DMC. The synthesis was carried out in both dimethyl sulfoxide (DMSO) and methanol. Methanol is preferred, as it not only served as a reagent and solvent in CO2 capture and DMC synthesis, but it also assisted in controlling the side reactions between chemical species such as CH3I and [DBUH]+ cation and increased the yield of DMC. Hence, the use of methanol avoided the loss of captured CO2 and favored the formation of DMC with high selectivity. Under the applied reaction conditions, 89% of the captured CO2 was converted to DMC. DBU was obtained, achieving 86% recovery of its salts formed during the synthesis. Most importantly, in this report we describe a simple and renewable solvent-based process for a metal-free approach to DMC synthesis under industrially feasible reaction conditions.

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