Asha V. Chate

超声辅助多组分反应:水介质中以β-环糊精为可重复使用的超分子催化剂绿色合成氮取代的1,8-二氧-十氢吖啶

We demonstrate a superficial method for the synthesis of N-substituted 1,8-dioxo-decahydroacridines using β-cyclodextrin as a supramolecular, biodegradable, and reusable catalyst in aqueous medium. The reaction product is in excellent yield with moderate to excellent selectivity. The mechanistic transformation presumably proceeds via a one-pot, multicomponent cyclization of dimedone in the presence of aromatic aldehydes and aromatic amines/INH, undergoing a tandem Michael addition reaction. The proposed approach in this study provides a highly efficient and environmentally benign route to N-substituted 1,8-dioxo-decahydroacridines.

Synthesis and Antimicrobial Evaluation of New 5-(2-Hydroxyphenyl)-3-(4-(Phenylthio)Phenyl)-1H-Pyrazole-2(5H)-Carbothioamide Analogues of 2-(4-(Phenylthio)Phenyl)-4H-Chromen-4-One

Abstract A series of novel 5-(2-hydroxyphenyl)-3-(4-(phenylthio)phenyl)-1H-pyrazole-2(5H)-carbothioamide derivatives have been synthesized via the ring opening of 2-(4-(phenylthio)phenyl)-4H-chromen-4-one with semicarbazide in ethanol and KOH under ultrasonic irradiation. The synthesized compounds were screened for antibacterial and antifungal activity against bacteria Staphylococcus aureus (MRSA E710) and Escherichia coli (25922) and fungi Candida albicans and Aspergillus fumigates, respectively. Some of the tested compounds showed significant antimicrobial activity. IR, 1H NMR, mass spectral data, and elemental analysis elucidated the structures of all the newly synthesized compounds. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Biological Assay. GRAPHICAL ABSTRACT

Ultrasonic Promoted Synthesis and Antibacterial Screening of Some Novel Piperidine Incorporated α-Aminophosphonates

Abstract A simple and high-yielding method was developed for the synthesis of novel α-aminophosphonates from imines, obtained from 4-(piperidine-1-yl)benzaldehyde, by using triethylphosphite in the presence of dilute HCl under ultrasound irradiation. This method, which was developed for the synthesis of α-aminophosphonates, gave excellent yields. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT

Efficient approach to thiazolidinones via a one-pot three-component reaction involving 2-amino-1-phenylethanone hydrochloride, aldehyde and mercaptoacetic acid

Abstract A highly efficient three-component reaction has been developed for the synthesis of thiazolidinones involving the reaction of 2-amino-1-phenylethanone hydrochloride with an aromatic aldehyde and mercaptoacetic acid in the presence of diisopropylethylamine in a single pot. Critically, this reaction exhibited excellent chemoselectivity, with the nitrogen atom of the 2-amino-1-phenylethanone component reacting selectively with the aromatic aldehyde to give the corresponding Schiff base. Nucleophilic attack at the carbon of the Schiff base by the sulfur atom of mercaptoacetic, followed by a cyclocondensation reaction between the nitrogen and the carboxylic acid moiety afforded the desired thiazolidinones, which were fully characterized by spectroscopic techniques.

Lithium bromide catalyzed efficient and convenient synthesis of 2-arylbenzothiazole derivatives

A new and efficient protocol was developed for synthesis of benzothiazoles using lithium bromide as catalyst under environmentally friendly conditions. The developed synthetic protocol represents a novel and very simple route for preparation of 2-substituted benzothiazole derivatives. In addition, an ultrasound irradiation technique is successfully implemented for carrying out the reactions in shorter reaction times.

Synthesis, Antioxidant, Anti-Inflammatory, and Antimicrobial Screening of Newer Thiophene-Fused Arylpyrazolyl 1,3,4-Oxadiazoles

GRAPHICAL ABSTRACT Abstract A series of newer 1,3,4-oxadiazole derivatives 3a–h, 5a–h containing a thiophene fused with pyrazole moiety of pharmacological significance have been synthesized. The compounds were characterized by 1H NMR, IR, and mass spectral techniques. The compounds were screened for their in vitro antioxidant, anti-inflammatory and antimicrobial activities. Among them, Compounds 3b (EC50–14.98) and 3f (EC50–12.21) showed significant antioxidant activity. Compound 3a (EC50–15.23) showed good anti-inflammatory activity. Compound 3d was found as the most active derivative against bacterial and fungal strains.

Baker’s yeast: An efficient, green, and reusable biocatalyst for the one-pot synthesis of biologically important N-substituted decahydroacridine-1,8-dione derivatives

ABSTRACT A green approach for one-pot three-component synthesis of N-substituted decahydroacridine-1,8-diones is offered for the first time using baker’s yeast (Saccharomyces cerevisiae) as a biocatalyst under ultrasonication. Due to growing safety and environmental concerns, enzymatic methods were constantly investigated as an attractive alternative to toxic and nonspecific chemical approaches. This method is relatively simple, efficient, inexpensive, and environment-friendly. The catalyst was recovered and reused and also the recyclability of baker’s yeast resulted in excellent yields of products without loss of any catalytic activity. GRAPHICAL ABSTRACT

β-Cyclodextrin catalyzed one-pot four component auspicious protocol for synthesis of spiro[acridine-9,3′-indole]-2′,4,4′(1′H,5′H,10H)-trione as a potential antimicrobial agent

ABSTRACT We have developed an perceptive and facile approach for the synthesis of new spiro[acridine-9,3′-indole]-2′,4,4′(1′H,5′H,10H)-trione derivatives (4a–t) by one-pot four component condensation involving two equivalence of dimedone (1), substituted anilines (2a–t), and isatin (3) catalyzed by β-cyclodextrin in water within short reaction time at 80 °C in good to excellent yields. We believe that this novel procedure may open the door for the easy generation of new and bioactive spiro[acridine-9,3′-indole]-2′,4,4′(1′H,5′H,10H)-triones. The most exciting feature of this methodology is its mechanism involving the unusual ring opening of an isatin moiety followed by recyclization. Synthesized compounds were evaluated for their antimicrobial activities against four bacteria and three fungi. All the spirooxindole derivatives exhibited significant antibacterial activity against bacteria and fungi. Among 20 compounds screened, compound (4i) and (4h) was found to be more active against tested bacterial strain. GRAPHICAL ABSTRACT

β-CD-catalyzed multicomponent domino reaction: synthesis, characterization, in silico molecular docking and biological evaluation of pyrano[2,3- d ]-pyrimidinone derivatives

Simple and green synthetic procedures constitute an important goal in organic synthesis. The combination of multicomponent reactions (MCRs) and unconventional solvents has become a new research direction, which enables simultaneous growth of both MCRs and green solvents toward ideal organic synthesis. In this paper, we have summarized recent results of MCRs obtained in unconventional media using water and β-cyclodextrin, as supramolecular catalyst, for the synthesis of pyrano[2,3-d]-pyrimidinone (4a–q) derivatives. The compounds were evaluated for their in vitro antimicrobial activity. Among the synthesized compounds, compounds 4h, 4m and 4p exhibited higher antimicrobial activity than ciprofloxacin used as the reference drug. Most of the synthesized compounds have good to excellent antimicrobial activity. Furthermore, \ molecular docking study was performed to help understand binding interactions of the most active analogs with C30 carotenoid dehydrosqualene synthase enzyme.Graphical Abstract

AN EFFICIENT AND GREEN PROTOCOL FOR THE SYNTHESIS OF DIHYDROPYRANO [2,3-C] PYRAZOLES IN AQUEOUS MEDIUM USING THIAMINE HYDROCHLORIDE AS A CATALYST

A green and expedient approach for the synthesis of dihydropyrano[2,3-c] pyrazoles via four-component reaction of ethyl acetoacetate, hydrazine hydrate, aromatic aldehydes and malononitrile at room temperature under ultrasound irradiation is described. The reaction has been catalyzed by thiamine hydrochloride in aqueous medium. This protocol afforded several advantages such as inexpensive, easily available catalyst, simple operational procedure, excellent yield, use of aqueous medium and ultrasound irradiation that is considered to be relatively eco-friendly.