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A one-pot three-component approach for the synthesis of dihydrofuro[3,2-c]coumarins was developed via the reaction of aryl/hetryl aldehydes, substituted phenacyl bromides and 4-hydroxycoumarin using N,N-diisopropyl ethyl ammonium acetate as the promoting medium.

Green protocols for the syntheses of 3,3′-arylidenebis-4-hydroxycoumarins and dimethyl ((substituted phenyl) (phenylamino)methyl) phosphonates have been first time developed using biocatalyst, CAL-B (lipase). These are carried at room temperature under stirring and are convenient and cost effective. The developed protocols are environmentally acceptable and are giving better to excellent yields of the titled products.

Herein, a fast and convenient protocol for the synthesis of new isoniazid fused chromeno[4,3-b]quinolin was achieved through biomimetic catalysis by cyclodextrin in the water at 60–65 °C. The present investigation involves attractive characteristics such as the use of water as the reaction medium, one-pot conditions, short reaction periods, easy work-up/purification and reduced waste production. This method provides a green route for the synthesis of targeted scaffolds and also a wide substrate scope for several substituted aldehydes to provide good yields of the corresponding products. Furthermore, the catalyst can be easily recovered by simple filtration and reused several times without any substantial loss in activity. Our study also discloses the antimicrobial screening of new chromeno[4,3-b]quinolin-isonicotinamides against four bacterial and three fungal strains.

In the present study, we have developed an efficient and green method for the synthesis of pyrano[2,3-d]pyrimidine-2,4,7-triones employing β-cyclodextrin as a catalyst in aqueous media from substituted aldehydes, barbituric acid and meldrum acid. The reactions were performed under mild conditions to afford biologically active target molecules in excellent yields. All the synthesized compounds are evaluated for their in vitro anticancer activity against HePG-2 (Human liver cancer cell line) and MCF-7 (Human breast cancer cell line). Among them 4c, 4j, 4k, 4l and 4m were active and potent anticancer agents.

Water mediated and baker’s yeast catalyzed, efficient synthetic routes have been first time developed for multicomponent cyclocondensations leading to bioactive tetrahydrobenzo[a]xanthene-11-ones (4a–h) and pyrazolo[3,4-b]quinolines (7a–i). The developed protocols are conducted at room temperature and gave better to excellent yields of the titled compounds. The biocatalytical resource, activated baker’s yeast is readily available, and biodegradable. These protocols are more convenient, scalable, and obey most of the green principles also. The developed protocols are cost effective and better in operation than existing ones.

A library of new sulfonyl decahydroacridine-1,8-diones has been efficiently synthesized by the one-pot three-component reactions of 4-(p-tolyl sulfonoxy) benzaldehyde, dimedone, and amines in choli...

A series of dihydropyranochromenes and chromenopyrimidine-2,5-diones having chromene scaffold were synthesized via efficient multicomponent protocol in aqueous β-cyclodextrin. The reaction is free ...

An efficient and simple one-pot protocol has been developed for synthesis of substituted derivatives of 2-hydrazono-4-thiazolidinone-5-acetic acids 4a–j and 6a–g by cyclocondensation of aryl/pyrazolyl aldehyde, thiosemicarbazide and maleic anhydride in acetonitrile in the presence of readily available whole cell biocatalyst, baker’s yeast (Saccharomyces cerevisiae). The reaction is enhanced by ultrasonication.

The present method provides a wide scope and quick access to dihydropyrido[2,3-d:6,5-d′]dipyrimidinetetraone and pyrimido[4,5-d]pyrimidine derivatives in good to excellent isolated yields from a one-pot three-component reaction of aldehydes, barbituric acid and ammonium acetate/urea in DIPEAc at room temperature. Major advantages of the present methodology are: use of green solvent, short reaction time, catalyst free, compatibility with a wide range of substrates, ease of recovery, reusability of the reaction medium, and DIPEAc as an alternative solvent and catalyst. All the synthesized compounds (3a–k) and (4a–g) were evaluated for their in vitro anticancer and tyrosinase inhibitory activity. In vitro anticancer screening of the synthesized compounds was performed against MCF-7, HeLa and A-549 cancer cell lines and 3f, 3h and 3i showed good activity. The compounds 3a, 3c, 3f and 3i showed good in vitro anticancer activity against SK-MEL-2. The synthesized compounds were also tested on non-tumorigenic MCF-10A cell lines and were found to be selective towards their cancer cell lines. At the IC50 concentration of compound 3f there were typical morphological changes such as cell wall deformation, cell detachment, cell shrinkage and a reduced number of viable cells in MCF-7 cancer cell lines in comparison to control cells. Among the series, compounds 3f, 3h and 3i excellently inhibited the tyrosinase enzyme. A molecular docking study of the compounds was also performed and compounds showed overall very effective binding modes and good agglomeration in the active site by forming various interactions with active site residues. The in silico ADMET properties of the synthesized compounds showed that they possess worthy oral drug like properties.

An economical and efficient synthesis of dipyrimido-dihydropyridines and pyrimido[4,5-d]pyrimidines is described using greener and recyclable β-cyclodextrin as a supramolecular catalyst in aqueous ...

Substituted phenacyl chlorides (1a–f) were cyclocondensed with nucleophiles thiourea (2a) and thiobenzamide (2b) in presence of baker’s yeast (Saccharomyces cerevisiae) as whole-cell enzyme source in acetonitrile at room temperature to obtain 4-(4-substituted phenyl)thiazol-2-amines (3a–f) and 4-(substituted phenyl)-2-phenylthiazoles (4a–f), respectively. Moreover, substituted phenacyl chlorides also reacted with nucleophiles 2-amino-1,3,4-thiadiazole (2c), o-phenylenediamine (2d), 1-amino-2-mercapto-5-phenyl triazole (2e), and pyridin-2-amine (2f) at room temperature in presence of baker’s yeast to give fused heterocycles 6-(4-substituted phenyl)-2-phenylimidazo[2,1-b][1,3,4]thiadiazoles (5a–f), 2-(4-substituted phenyl)quinoxalines (6a–f), 6-(4-substituted phenyl)-3-phenyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines (7a–f), and 2-(4-substituted phenyl)H-imidazo[1,2-a]pyridines (8a–f), respectively. The experimental conditions for these cyclocondensations were optimized to obtain the biodynamic heterocycles in high yield. The unique features of this work are use of baker’s yeast as a cheap and readily available natural source of biocatalyst, noticeable rate acceleration, convenient route to products, cost effectiveness, and scalability.

Supramolecular β-cyclodextrin as a highly efficient, biodegradable, and reusable catalyst for the synthesis of 4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carbonitrile derivatives (4a–s) is investigated via a cascade reaction of aldehydes, malanonitrile and 2-aminopyridine in aqueous medium at 65 °C under ultrasonication. This procedure has the advantages of good yields, easy work-up, and benign environment friendly character. All of the synthesized derivatives were evaluated for their in vitro antibacterial activity against four bacterial strains.

Organopromoter, 2-aminoethanesulfonic acid was used to catalyze the synthesis of a series of structurally intriguing new hybrids thiazolyl acridine-1,8(2H,5H)-diones and dihydropyrido[2,3-d : 6,5-d']dipyrimidine-2,4,6,8(1H,3H,5H,7H)-tetraones for the first time. 2-Aminoethanesulfonic acid is a biobased organopromoter, used to generate four new bonds for the synthesis of new coupled thiazole-based decahydroacridine-1,8-diones. Superior green credentials, operational simplicity, easy work-up and recyclability of the catalyst are the key strengths of this method. The broad substrate scope, mild reaction conditions, short reaction time, cost effectiveness, high atom economy and good to excellent yields make the present method a distinct improvement over existing methods. Spectral (IR, 1 H-NMR,13 C-NMR, Mass) data and elemental analyses confirmed the structures of the titled products. A series of thiazolyl acridine-1,8(2H,5H)-diones and dihydropyrido[2,3-d : 6,5-d']dipyrimidine-2,4,6,8(1H,3H,5H,7H)-tetraones were screened for their antimicrobial activity against four bacterial and three fungal strains.

We report synthesis and in vivo antihyperglycemic evaluation of new 3-substituted phenyl-2-(4-(tetrazolo[1,5-a]quinolin-4-ylmethoxy)phenyl)thiazolidin-4-ones (8a–l). The title 4-thiazolidinones were synthesized by one-pot cyclocondensation of new 4-(tetrazolo[1,5-a]quinolin-4-ylmethoxy)benzaldehyde (5), anilines, and mercaptoacetic acid in PEG-400. The required aldehyde (5) was also synthesized, starting from 2-chloroquinoline-3-carbaldehyde via a successive multistep route. The newly synthesized products were thoroughly characterized based on their spectral data. Amongst them, compounds 8a–g, j exhibited notable in vivo antihyperglycemic activity. Compounds 8f, g showed percentage improvement in oral glucose tolerance of 18.9 and 20.7, respectively, compared with 28.3 for the reference metformin.

A convenient synthesis of 6-amino-2 H ,4 H -pyrano[2,3- с ]pyrazole-5-carbonitriles has been accomplished by one pot four-component cyclocondensation of aromatic aldehydes ( 1a-o ) malanonitrile ( 2 ), ethyl acetoacetate ( 3 ), and hydrazine hydrate ( 4 ) in freshly prepared deep eutectic solvent, DES (choline chloride:urea). This protocol has afforded corresponding pyrano[2,3- с ]pyrazoles in shorter reaction time with high yields, and it avoids the use of typical toxic catalysts and solvents.

The catalytic potential of tris(hydroxymethyl)aminomethane (Tromethamine) has been assessed for the one pot three component tandem reaction involving a thiazolylmethoxy phenyl/aromatic carboxaldehyde, substituted amines and thioglycolic acid to form new thiazolyl-4-thiazolidinones and known substituted-4-thiazolidinones. This strategy involves the use of tromethamine as a reusable promoter and water as an eco-friendly reaction medium. The merits of this protocol are high atom economy, mild reaction conditions, good yields of desired products in short reaction times, and reusable reaction medium. The generality and functional tolerance of this convergent and environmentally benign method is demonstrated.

A convenient one-pot, rapid and scalable synthetic protocol has been developed for recently reported anti-inflammatory agents, thiazole-substituted pyrazolyl-4-thiazolidinones. Quantitative multicomponent cyclocondensation of 3-(4-methyl-2-substituted thiazol-5-yl)-1-phenyl-1H-pyrazole-4-carbaldehydes (5a, b), amines and mercaptoacetic acid has been carried out in safer medium, diisopropylethylammonium acetate, at room temperature. The optimisation details of the developed novel protocol are recorded.

New trisubstituted pyrazoles bearing thiazolyl and thiazolidinonyl moieties have been successfully and conveniently synthesized in three steps using 5-acetyl thiazoles (1a–b) as starting materials. The route includes the synthesis of new intermediates, 4-formyl 5-thiazolyl pyrazoles (4a–b). The formyl pyrazoles on one pot cyclocondensation with anilines and thioglycolic acid have been found to yield the titled compounds (7a–j). The new pyrazoles have been screened to evaluate in vivo anti-inflammatory activity and compounds 7c, 7d, 7f, 7g, 7h, and 7i have better anti-inflammatory activity than reference drug Celecoxib. The synthetic details and results of anti-inflammatory activity are discussed.

Here we report a novel Baker yeast catalysed one pot cyclocondensation, carried at room temperature in ethanol for obtaining high yields of polyfunctionalised pyridines, 2-amino-4-aryl-3,5-dicyano-6-phenylthio-pyridines. The developed protocol obeys certain green principles and is scalable and cost effective.

A simple and efficient protocol developed for the synthesis of 5-substituted 1H-tetrazole derivatives through [2+3] cycloaddition reaction between benzonitriles and sodium azide using diisopropylethylammonium acetate as a recyclable reaction medium is described. The reactions proceed well at 80 °C and provide the corresponding tetrazoles in good to excellent yields (up to 94% yield). Developed method has notable advantages, such as simple and mild conditions, easy workup, reusability with consistent catalytic activity, and safer alternative to hazardous, corrosive conventional Lewis acid catalysts.

Background: 2, 4-Thiazolidinedione (TZD), pyrazole and thiazole heterocyclic rings exhibit a wide range of pharmacological activities. Medicinal chemists use these heterocyclic moieties as scaffolds in drug designing and discovery. The existing medicaments, celecoxib and meloxicam, used for treating inflammation and pain are having, pyrazole and thiazole, respectively as key scaffolds. Pyrazoles coupled with 2, 4-thiazolidinediones may display enhanced anti-inflammatory activity. With this hope the bench work was carried out. Methods: Heterocyclic aldehydes, 3-(4-methyl-2-substituted thiazol-5-yl)-1-phenyl-1Hpyrazole- 4- carbaldehydes (4a-b) have been allowed to undergo Knoevenagel condensation with N-substituted 2,4-thiazolidinediones (5a-e) in PEG-400 in the presence of L-proline at 110°C and obtained the condensed products (6a-j). COX-2 evaluation of the titled product has been carried out using in vitro COX-2 ELISA Kit. Antibacterial activity of these compounds (6a-j) has also been determined. Results: On the basis of 1H NMR, 13C NMR and Mass spectral data of the condensed products the structures have been assigned to (Z)-5-((3-(4-methyl-2-substituted thiazol-5-yl)-1- phenyl-1H-pyrazol-4-yl)methylene) 3-substituted thiazolidine-2,4-diones (6a-j). Among the evaluated compounds (6a-j), 6f, 6g, 6h, 6i and 6j have shown notable COX-2 inhibitory activity. Conclusion: Compounds, 6a, 6b, 6c, 6d, 6e and 6f have inhibited the growth of the Bacillus cereus NCIM 2106, Bacillus subtilis NCIM 2063, Pseudomonas aeruginosa NCIM 2074, Salmonella typhimurium NCIM 2501 and Staphylococcus aureus NCIM 2079. However, compound 6f has emerged as a suitable candidate with dual properties i.e. COX-2 inhibitory and antibacterial in the present study.

The environmentally friendly ultrasound promoted method offers several advantages such as operational simplicity, easy work-up procedure, shorter reaction times, and high yields.

A convenient synthetic route has been developed to synthesize 5-(4-((2-phenylthiazol-4-yl) methoxy)phenyl)3-(4-sustituted phenyl)pyrazolines (5a-f) and 5-(4-((2-phenylthiazol-4-yl)methoxy)phenyl)-3-(4-substituted phenyl)isoxazolines (6a-f) starting from 2-phenyl-4-chloromethylthiazole (1). The chloromethylthiazole (1) was first condensed with 4-hydroxy benzaldehyde (2) for obtaining 4-((2-phenylthiazol-4-yl)methoxy)benzaldehyde (3). Claisen-Smidth condensation of 4-((2-phenylthiazol-4-yl)methoxy)benzaldehyde (3) and acetophenones has been carried in alkaline alcohol and obtained 3-(4-((2-phenylthiazol-4-yl)methoxy)phenyl)-1-(4substituted phenyl)prop-2-en-1-ones (4a-f). The cyclocondensation of 2-propen-1-ones has been first time carried separately with hydrazine hydrate and hydroxylamine hydrochloride in aqueous micellar tetradecyltrimethylammonium bromide (TTAB) medium for getting the titled heterocycles with good to excellent yields.

An efficient one-pot three-component cyclocondensation of 4-(p-toulyl sulfonoxy) benzaldehyde, aryl amines, and mercaptoacetic acid in polyethylene glycol 400 (PEG-400) was conducted to obtain new 2,3-disubstituted-4-thiazolidinones. This route is economical and ecofriendly. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:166–170, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20766

There is no report on the synthesis of 2,4-thiazolidinediones bearing heteryl substituents like, piperidinyl quinolines. Keep-ing the above potent usefulness of the heterocycles in mind, here it was thought worthwhile to synthesize the titled, new quinolidinyl 2,4-thiazolidinediones with hope to obtain the molecules with potential hypoglycemic activity by developing a convenient synthetic route using readily available starting materials. It has also been reported

Saccharomyces cerevisiae (baker’s yeast) catalyzed one-pot three component cyclocondensation of aryl aldehydes, amines, and thioglycolic acid in organic medium leading to 2,3-diaryl 4-thiazolidinones has been carried out for the first time.

In the search of new antihyperglycemic agents and following rational approach of drug designing here new 2-hydrazolyl-4-thiazolidinone-5-carboxylic acids ( 4a – g ) with pyrazolyl pharmacophore have been synthesized via thia Michael addition reaction of 1-((3-(4-substituted phenyl)-1-phenyl-1 H -pyrazol-4-yl)methylene)thiosemicarbazides ( 3a – g ) with maleic anhydride. The required precursors, ( 3a – g ) were obtained by condensing known 3-(4-substituted phenyl)-1-phenyl-1 H -pyrazole-4-carbaldehydes ( 1a – g ) with thiosemicarbazide in ethanol. The newly synthesized compounds ( 4a – g ) have been evaluated for the antihyperglycemic activity in sucrose loaded rat model and among these compounds 4d , 4f and 4g have displayed significant antihyperglycemic activity.

An efficient one-pot three-component cyclocondensation of 4-(p-toulyl sulfonoxy) benzaldehyde, aryl amines, and mercaptoacetic acid in polyethylene glycol 400 (PEG-400) was conducted to obtain new 2,3-disubstituted-4-thiazolidinones. This route is economical and ecofriendly. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:166–170, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20766

Saccharomyces cerevisiae (baker’s yeast) catalyzed one-pot three component cyclocondensation of aryl aldehydes, amines, and thioglycolic acid in organic medium leading to 2,3-diaryl 4-thiazolidinones has been carried out for the first time.

under microwave irradiation conditions using polyethylene glycol 400 as reaction medium and catalyst