Synthesis and Biological Evaluation of Novel Chalcone and Pyrazoline Derivatives Bearing Substituted Vanillin Nucleus

A series of novel chalcone 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l and pyrazoline 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l derivatives have been synthesized as potential antibacterial agents. The pyrazoline derivatives 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l have been synthesized by reaction of various chalcones 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l with hydrazine hydrate in the presence of acetic acid. The chalcones 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l were prepared by the condensation of key aldehyde 3 with appropriate acetophenone using basic condition and ethanol as a solvent. The key aldehyde 3 has been synthesized by reacting 2‐(chloromethyl)‐3‐methyl‐4‐(2,2,2‐trifluoroethoxy)pyridine hydrochloride and vanillin. The structures of the new compounds were established on the basis of ¹H‐NMR, mass, IR, and elemental analysis data. All the newly synthesized compounds were screened for their antibacterial activity against Escherichia coli, Salmonella typhi (Gram‐negative bacteria), Staphylococcus aureus, Micrococcus luteus (Gram‐positive bacteria) and antifungal activity against Candida albicans (fungi).     

Synthesis,characterization, and in vitro biological studies of some novel pyran fused pyrimidone derivatives

A variety of pyrano[2,3‐d]pyrimidine‐5‐one derivatives 5 , 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 6 , 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j have been synthesized from 6‐amino‐4‐(substituted phenyl)‐5‐cyano‐3‐methyl‐1‐phenyl‐1,4‐dihydropyrano[2,3‐c]pyrazole derivatives 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j via cyclization using formic acid and acetic acid. All the newly synthesized compounds have been characterized by IR, ¹H NMR, ¹³C NMR, and elemental analysis. All the synthesized compounds have been screened for antibacterial, antifungal and antitubercular activity. J. Heterocyclic Chem., (2012).     

Synthesis and antimicrobial activity of some 7‐aryl‐5,6‐dihydro‐14‐aza[1]benzopyrano[3,4‐b]phenanthren‐8H‐ones

The title compounds, 7‐aryl‐5,6‐dihydro‐14‐aza[1]benzopyrano[3,4‐b]phenanthren‐8H‐ones 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l have been synthesized by reacting various 4‐hydroxy coumarins 1a , 1b , 1c with 2‐arylidene‐1‐tetralones 2a , 2b , 2c , 2d in the presence of ammonium acetate and acetic acid under Krohnke's reaction condition. The structures of all the synthesized compounds were supported by analytical, IR, ¹H‐NMR, and ¹³C‐NMR data. All the synthesized compounds 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l have been screened for their antibacterial activities against Escherichia coli (Gram ?ve bacteria), Bacillus subtilis (Gram +ve bacteria), and antifungal activity against Candida albicans (Fungi). J. Heterocyclic Chem., (2011).     

Synthesis and Antimicrobial Activity of Some Novel [4‐(1,2,3‐thiadiazol‐4‐yl)phenoxy]methylene anchored 1,3,4‐triazoles and 1,3,4‐thiadiazoles

A series of novel [4‐(1,2,3‐thiadiazol‐4‐yl)phenoxy]methylene anchored 1,3,4‐triazoles ( 8a , 8b , 8c , 8d , 8e , 8f , 8g , 8h ) and 1,3,4‐thiadiazoles ( 9a , 9b , 9c , 9d , 9e , 9f , 9g , 9h , 9i ) were synthesized from thiosemicarbazide ( 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j ). The structures of these newly synthesized compounds were confirmed on the basis of IR, ¹H‐NMR, mass spectral techniques, and elemental analysis. The in vitro antimicrobial screenings of the synthesized compounds were carried out against four bacterial pathogens, namely Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa and three fungal pathogens Candida albicans, Aspergillus niger and Aspergillus clavatus, using broth microdilution minimum inhibitory concentration method. The compounds 7d , 7j , 8a , 9a , 9b , and 9i exhibited promising antibacterial activity against the tested strains, whereas some compounds were found to be active against one of the tested bacterial strains.     

Synthesis and In Vitro Antimicrobial Screening of New Azetidin‐2‐ones of 5‐Ethyl Pyridine‐2‐ethanol

A new series of azetidinones is described in this paper; Schiff base ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l , 4m , 4n , 4o ) were synthesized from 4‐[2‐(5‐ethylpyridin‐2‐yl)ethoxy]benzaldehyde, which was used to synthesize azetidinones ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l , 5m , 5n , 5o ), ( 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j , 6k , 6l , 6m , 6n , 6o ), and ( 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j , 7k , 7l , 7m , 7n , 7o ). The structures of the synthesized compounds were assigned on the basis of elemental analysis, IR, ¹H NMR, and ¹³C NMR spectral data. All the products were screened against different strains of bacteria and fungi. Most of the monosubstituted and disubstituted chloro groups are more effective to both bacterial and fungal species in comparison with the standard drugs.     

Synthesis and Bioassay of Novel Substituted Pyrano[2,3‐f]cinnoline‐2‐ones

A new series of 9‐substituted‐4,10‐dimethylpyrano[2,3‐f]cinnolin‐2‐ones ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l , 5m ) were synthesized via intramolecular cyclization of the respective acyl amidrazone derivatives ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l , 4m ), catalyzed by polyphosphoric acid. Compounds ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l , 4m ) were synthesized through direct interaction of coumarin‐7‐yl hydrazonoyl chloride ( 3 ) with the corresponding cyclic sec‐amines in the presence of triethylamine. The structures of the new compounds were confirmed by elemental analyses, NMR, and MS spectral data. The antitumor activity of compounds 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l , 5m was evaluated in vitro on breast cancer cell line (MCF‐7) by a cell viability assay utilizing the tetrazolium dye 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide. Among the compounds tested, compounds 5d , 5f , 5k , and 5h showed potential anti‐MCF‐7 activity and were able to reduce the viability after 72 h to less than 50%.     

Synthesis,Structural Characterization,and Biological Evaluation of Novel Substituted 1,3‐Thiazole Derivatives Containing Schiff Bases

In this study, thiazole derivatives containing Schiff bases ( 7a , 7b , 7c , 7d , 7e , 7f , 8a , 8b , 8c , 8d , 8e , 8f , 9a , 9b , 9c , 9d , 9e , 9f ) were synthesized in moderate to high yields (49–94%) using the Hantzsch reaction with thiosemicarbazone derivatives ( 5a , 5b , 5c ) and 2‐bromo‐1‐phenylethanone derivatives ( 6a , 6b , 6c , 6d , 6e , 6f ). The structures of synthesized compounds were elucidated by IR, ¹H NMR, ¹³C NMR, elemental analyses, mass spectroscopy and X‐ray diffraction analysis techniques. Moreover, the synthesized compounds were tested for their in vitro antifungal activity and most of them exhibited moderate to good activity against Fusariumoxysporumf.sp. lycopersici.      

Synthesis of Cytotoxic Isodeoxypodophyllotoxin Analogs

A series of aryltetralin lignans 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j , 7k , 7l were synthesized as cytotoxic isodeoxypodophyllotoxin analogs. The title compounds 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j , 7k , 7l were synthesized from the reaction of (+)‐(R )‐4‐[benzo(d )(1,3)dioxol‐5‐ylmethyl]‐dihydrofuran‐2‐(3H )‐one with different arylaldehydes to afford benzyl alcohol analogs and subsequent cyclization with trifluoroacetic acid in dichromethane. The preliminary screening of the compounds against viability of blood cancer human cell line K562 revealed that compounds 7d , 7e , and 7f had higher inhibitory activity at 10 µg/mL concentration compared with etoposide as reference drug.     

Synthesis and Antimicrobial Activity of Some Novel Substituted Bis‐Pyridone,Pyrazole, and Thiazole Derivatives

A variety of novel bis‐heterocyclic derivatives were synthesized via the reaction of bis‐cyanoacetanilide derivative 3 with various aromatic aldehydes (1:2 molar ratio), to give the corresponding bis‐arylidene derivatives 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l , 5m . On the other hand, reacting compound 3 with substituted 2‐hydroxybenzaldehydes 6a , 6b , 6c afforded 2‐iminochromene‐3‐carboxamides 7a , 7b , 7c . The reaction of compound 5 with malononitrile afforded the novel bis‐pyridones 9a , 9b , 9c , 9f , 9g , 9h . The reaction of 5 with hydrazine derivatives afforded pyrazoles 11a , 11b , 11c , 11d , 11e , 11f , respectively. Compound 3 reacts with phenyl isothiocyanate in the presence of potassium hydroxide at room temperature followed by addition of some different halo‐carbonyl compounds to afford bis‐poly‐functionalized thiazole derivatives 13a , 13b , 13c . The bis‐enamine derivative 15 reacts also with hydrazine hydrate, guanidine, and hydroxylamine to give bis‐pyrazole 17 , pyrimidine 19 , and isoxazole 21 derivatives, respectively. Some of the newly synthesized compounds show moderate to high antimicrobial activity.     

Synthesis,Characterization, and Antimicrobial Evolution of Bissydnone Based on Sulfonamide Derivatives

3,3′‐(Sulfonyldi‐1,4‐phenylene)bis(4‐substituted aminosulfonyl)sydnones ( 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j ) were synthesized from the starting material 4,4′‐diaminodiphenylsulfone. The synthesized compounds were characterized by IR, NMR, and elemental analysis. Some of the compounds were effectively active against Gram‐positive bacteria (Streptococcus pneumoniae and Staphylococcus aureus) and Gram‐negative bacteria (Escherichia coli and Pseudomonas aeruginosa).     

Synthesis and Antimicrobial Activity of Linked Heterocyclics Containing Pyrazole and Oxadiazoles

A new series of 3‐(arylaminomethyl)‐5‐(5‐methyl‐1‐phenyl‐1H‐4‐pyrazolyl)‐2,3‐dihydro‐1,3,4‐oxadiazole‐2‐thiones 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j has been synthesized by the reaction of 5‐(5‐methyl‐1‐phenyl‐1H‐4‐pyrazolyl)‐1,3,4‐oxadiazol‐2‐ylhydrosulfide 5 with formaldehyde and corresponding anilines. The chemical structures of newly synthesized compounds were elucidated by IR, ¹H, ¹³C‐NMR, MS, and elemental analyses. The compounds 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j were evaluated for their antibacterial activity against three representative Gram positive bacteria viz. Bacillus subtilis (MTCC 441), Bacillus sphaericus (MTCC 11) and Staphylococcus aureus (MTCC 96), and three Gram negative bacteria viz. Pseudomonas aeruginosa (MTCC 741), Klobsinella aerogenes (MTCC 39) and Chromobacterium violaceum. Among the screened 6b , 6d , 6i , and 6j in which oxadiazole moiety bearing 4‐fluoroanilinomethyl, 4‐chloroanilinomethyl, 2‐trifluoromethylanilinomethyl, and 2,5‐difluoroanilinomethyl groups, respectively, showed high activity against all the microorganisms used. In addition these compounds were also screened for their antifungal activity against four fungal organisms viz. Candida albicans (ATCC 10231), Aspergillus fumigatus (HIC 6094), Trichophyton rubrum (IFO 9185), and Trichophyton mentagrophytes (IFO 40996). Most of these new compounds showed appreciable activity against test fungi, and emerged as potential molecules for further development.     

Synthesis and Antimicrobial Activities of Novel Series of 3‐(4‐(2‐substituted thiazol‐4‐yl)phenyl)‐2‐(4‐methyl‐2‐substituted thiazol‐5‐yl)thiazolidin‐4‐one Derivatives

In the present investigation, a novel series of 3‐(4‐(2‐substituted thiazol‐4‐yl)phenyl)‐2‐(4‐methyl‐2‐substituted thiazol‐5‐yl)thiazolidin‐4‐one derivatives were synthesized by condensation of 2‐substituted‐4‐methylthiazole‐5‐carbaldehyde with 4‐(2‐substituted thiazol‐4‐yl)benzenamine followed by cyclo‐condensation with thioglycolic acid in toluene. All the newly synthesized compounds were characterized by spectral (IR, ¹H NMR, ¹³C NMR, and Mass) methods. The title compounds were screened for quantitative antibacterial activity (minimal inhibitory concentration). All compounds 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h and 8a , 8b , 8c , 8d , 8e , 8f , 8g , 8h show moderate to good antimicrobial activity, whereas compounds ( 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h ) also show moderate antifungal activity.     

Synthesis of Pyridotriazolopyrimidines as Antitumor Agents

2‐Hydrazino‐5,7‐di‐p‐tolylpyrido[2,3‐d ]pyrimidin‐4(3H )‐one ( 4 ) was prepared and condensed with different aldehydes 5a , 5b , 5c , 5d , 5e , 5f , 5g to give the corresponding hydrazone derivatives 6a , 6b , 6c , 6d , 6e , 6f , 6g . Oxidative cyclization of the latter compounds 6a , 6b , 6c , 6d , 6e , 6f , 6g gave the corresponding pyrido[2,3‐d ][1,2,4]triazolo[4,3‐a ]pyrimidin‐5(1H )‐ones 7a , 7b , 7c , 7d , 7e , 7f , 7g . Furthermore, compound 4 reacted with benzoyl chloride, triethyl orthoformate, acetyl chloride, ethyl chloroformate, and carbon disulphide in alcoholic KOH solution to afford the corresponding pyrido[2,3‐d ][1,2,4]triazolo[4,3‐a ]pyrimidinones ( 7a , 8 , 9 , 10 , 11 ). The reaction of thione 3 or its 2‐methylthio derivative 16 with hydrazonoyl halides 12a , 12b , 12c , 12d , 12e , 12f , 12g , 12h , 12i , 12j , 12k , 12l , 12m yielded the corresponding pyrido[2,3‐d ][1,2,4]triazolo[4,3‐a ]pyrimidinones 15a , 15b , 15c , 15d , 15e , 15f , 15g , 15h , 15i , 15j , 15k , 15l , 15m . The structures of all the products were confirmed by elemental and spectral analyses (¹H NMR, ¹³C NMR, IR, and MS). In addition, the anticancer activity of 20 pyridotriazolopyrimidinones against two cancer cell lines namely MCF‐7 and HepG2 was evaluated, and the results revealed that compounds 7d and 9 have promising activity , compared with doxorubicin, which used as standard reference drug.     

Synthesis of New 2,4‐Diaryl‐6‐methyl‐5‐nitropyrimidines as Antibacterial and Antioxidant Agents

A new series of 2,4‐diaryl‐6‐methyl‐5‐nitropyrimidines ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i ) were synthesized in good yields by Suzuki–Miyaura coupling of 2,4‐dichloro‐6‐methyl‐5‐nitropyrimidine ( 3 ) with various aryl boronic esters ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i ) in the presence of 1,1′‐ bis(diphenylphosphino)ferrocene dichloropalladium(II) (Pd(dppf)₂Cl₂). Further, antibacterial and antioxidant properties were screened for the title compounds 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i . Most of the compounds possessed significant activity against Gram‐positive bacteria Staphylococcus aureus and Bacillus subtilis and Gram‐negative bacteria Escherichia coli and Klebsiella pneumoniae. The antioxidant activity of the title compounds showed significant antioxidant activity when compared with vitamin C.     

Synthesis and Biological Activities of Some New Annulated Pyrazolopyranopyrimidines and Their Derivatives Containing Indole Nucleus

The key intermediate 6‐amino‐3‐methyl‐4‐aryl‐1‐(5′‐substituted‐3′‐phenyl‐1H‐indol‐2′‐carbonyl)‐1,4‐dihydropyrano[2,3‐c]pyrazol‐5‐carbonitriles 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l , 3m , 3n , 3o were prepared by cyclocondensation of 3‐methyl‐1‐(5′‐substituted‐3′‐phenyl‐1H‐indol‐2′‐carbonyl)‐5‐(4H)‐pyrazolones 1a , 1b , 1c with arylidine derivatives of malononitrile 2a , 2b , 2c , 2d , 2e . The compounds 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l , 3m , 3n , 3o were subjected to cyclocondensation reaction with formamide, formic acid, and carbon disulfide to afford the title compounds 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l , 4m , 4n , 4o , 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l , 5m , 5n , 5o , and 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j , 6k , 6l , 6m , 6n , 6o , respectively. The structures of all these previously unknown compounds were confirmed by their spectral studies and elemental analysis. These compounds were screened for their antimicrobial and antioxidant activities.     

4‐Toluenesulfonamide as a Building Block for Synthesis of Novel Triazepines,Pyrimidines, and Azoles

N‐{(E)‐(dimethylamino)methylidenearbamothioyl}‐4‐toluenesulfonamide ( 2 ) was obtained by reaction of N‐carbamothioyl‐4‐toluenesulfonamide ( 1 ) with dimethylformamide dimethylacetal or alternatively by the reaction of 1‐(dimethylamino)methylidenethiourea with tosyl chloride. Compound 2 was reacted with substituted anilines to yield anilinomethylidine derivatives 3a , 3b , 3c , 3d , 3e , 3f , 3g . Treatment of 3a , 3b , 3c , 3d , 3e , 3f , 3g with phenacyl bromide gave triazepines 4a , 4b , 4c , 4d , 4e , 4f , 4g and imidazoles 5a , 5b , 5c , 5d , 5e , 5f , 5g . Esterification of compound 3e afforded ester derivative 6 , which was subjected to react with hydrazine to yield hydrazide derivative 7 . Oxadiazole 8 was obtained by reaction of 7 with CS₂/KOH. Compound 3e was treated with o‐aminophenol or o‐aminothiophenol to give benzazoles 9a , 9b . N‐(Diaminomethylidene)‐4‐toluenesulfonamide ( 10 ) reacted with enaminones to yield pyrimidines 11 , 12 , 13 , respectively. The structures of the compounds were elucidated by elemental and spectral analyses. Some selected compounds were screened for their in vitro antifungal activity. In general, the newly synthesized compounds showed good antifungal activity.     

Synthesis of Oxazolo[5,4‐d][1,2,4]triazolo[4,3‐a]pyrimidines as a New Class of Heterocyclic Compounds

Several new derivatives of oxazolo[5,4‐d]pyrimidine ( 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h ) have been synthesized through the reaction of 2,4‐dichloro‐6‐methyl‐5‐nitropyrimidine ( 2 ) with aryl carboxylic acids in refluxing POCl₃. Further treatment of compounds ( 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h ) with hydrazine hydrate gave the hydrazine derivatives ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h ) that were subsequently cyclized into a novel heterocyclic system, oxazolo[5,4‐d][1,2,4]triazolo[4,3‐a]pyrimidine ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l , 5m , 5n , 5o , 5p ) and ( 7a , 7b , 7c , 7d ) on treatment with triethylorthoesters or carbondisulfide and alkylhalides, respectively.     

Novel Bis(2‐(5‐((5‐phenyl‐1H‐tetrazol‐1‐yl)methyl)‐4H‐1,2,4‐triazol‐3‐yl)phenoxy)Alkanes: Synthesis and Characterization

In this study, 10 different substituted aromatic bis‐benzaldehydes were synthesized by treating hydroxy benzaldehydes with various dihaloalkanes. Bis aldehydes 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j were treated with 2‐(5‐phenyl‐1H‐tetrazole‐1‐yl)acetohydrazide ( 3 ) in acidic medium and in the presence of ammonium acetate to yield a series of new isomeric bis(2‐(5‐((5‐phenyl‐1H‐tetrazol‐1‐yl)methyl)‐4H‐1,2,4‐triazol‐3‐yl)phenoxy)alkanes ( 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j ) in excellent to good yield. The newly synthesized compounds were characterized by the available spectroscopic analysis.     

Synthesis of some novel pyrazoline‐thiazole hybrids and their antimicrobial activities

A series of novel thiazolyl pyrazolines 7a‐h , 9a‐f , and 11a‐f have been synthesized by the reaction of thioamide derivatives 5a , b with 1‐aryl‐2‐bromoethanones 6a‐d , chloroacetones 8a‐c , and hydrazonoyl chlorides 10a‐c . Additionally, pyrazoles 15a‐c and 20 were prepared starting from enaminone 13 . These newly synthesized compounds were screened for their in vitro antibacterial activity against four bacterial species. Compound 11b showed a moderate activity against Klebsiella pneumoniae. Compounds 7c and 11c revealed a moderate activity against Pseudomonas aeruginosa. In addition, the antifungal activity of the newly synthesized compounds was determined against five fungal strains. Compounds 7e , 7g , and 11e showed a good activity against Aspergillus flavus and Penicillium expansum.     

Design and synthesis of new imidazolinone derivatives as potential antifungal agents

A new series of chalcones, pyrimidines, and imidazolinone is described; chalcones ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l , 4m , 4n , 4o ) were prepared from the lead 4‐[2‐(5‐ethylpyridin‐2‐yl)ethoxy]benzaldehyde. Pyrimidines ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l , 5m , 5n , 5o ) were prepared from the reaction of chalcones and guanidine nitrate in alkali media. Imidazolinones ( 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j , 6k , 6l , 6m , 6n , 6o ) were synthesized from the reaction of pyrimidine and oxazolone derivatives (prepared by Erlenmeyer azlactone synthesis). The structures of the synthesized compounds were assigned on the basis of elemental analyses, IR, ¹H‐NMR, and ¹³C‐NMR spectral data. All the products were screened against different strains of bacteria and fungi. Most of these compounds showed better inhibitory activity in comparison with the standard drugs. J. Heterocyclic Chem., (2011).