Synthesis, characterization and antimicrobial activity of some new 1-(fluorobenzoyl)-3-(fluorophenyl)thioureas

Synthesis of a variety of new 1-(isomeric fluorobenzoyl)-3-(isomeric fluorophenyl)thioureas (1a-t) was accomplished in two steps. The synthetic route involves the reaction of equimolar quantities of isomeric fluorobenzoyl chlorides with potassium thiocyanate in anhydrous acetone to afford the corresponding isothiocyantes in situ, followed by treatment with equimolar quantities of isomeric fluoroanilines. All of the synthesized compounds (1a-t) were screened for their in vitro antibacterial activity using Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aureginosa). The minimum inhibitory concentration (MIC) was also determined for the most active compounds. In vitro antifungal activity was also determined against the five fungal species (Rhizopus oryzae, Aspergillus tereus, Fusarium oxysporum, Aspergillus niger, Aspergillus fumigatus). In general, the antifungal activity of compounds was better than their antibacterial activity.     

Green Synthesis of Some New (Substituted Fluorobenzoylimino)-3-aryl-4-methyl-1,3-thiazolines

A series of 2-, 3-, and 4-substituted (fluorobenzoylimino)-3-aryl-4-methyl-1,3-thiazolines (2a–j) were synthesized in good yields by the base-catalyzed cyclization of corresponding 1-(fluorobenzoyl)-3-(fluorophenyl)thioureas (1a–j) with α-bromoacetone in water. Compared to the reactions in conventional nonaqueous solvents under inert anhydrous conditions, the aqueous medium provides a much cleaner, more efficient, and simpler method for synthesis.     

Synthesis and X-ray Structural Studies of 2-（2-Benzofuroylimino）-3-aryl-4-phenyl- 1,3-thiazolines

The synthesis for acyliminothiazolines by treatment of N, N□-substituted thioureas with α-bromoacetophenone under aqueous media was described. 2-（2-Benzofuroylimino）-3-aryl- 4-phenyl-1,3- thiazolines were characterized by infrared, NMR spectroscopy and elemental analysis. The single crystals of compounds 4a and 4b were grown by slow evaporation of 80% ethanol solution at room temperature. Compounds 4a and 4b crystallize in triclinic space group P1 and monoclinic space group P21/c, respectively.     

Synthesis and Crystal Structure of Some Novel 2-Aroylimino-3-aryl-4-phenyl-1,3-thiazolines

An efficient synthesis of some novel 2-aroylimino-3-aryl-4-phenyl-1,3-thiazolines was carried out by base-catalyzed cyclization of 1-aroyl-3-arylthioureas with acetophenone in the presence of bromine. The structures were confirmed by spectroscopic data, elemental analyses, and in one case (2t) by single-crystal X-ray diffraction data.     

3-(N-取代苯基-2-乙酰胺基)硫基-4-N-取代邻羟苯基亚胺基-5-甲基-1,2,4-三唑类化合物的合成及生物活性研究

以对称二氨基硫脲为原料,与冰醋酸反应生成5-甲基-4-氨基-1,2,4-三唑-3-硫酮(1);在弱酸性条件下,1与取代水杨醛反应生成席夫碱中间体5-甲基-4-(N-取代邻羟苯基)亚胺基-1,2,4-三唑-3-硫酮(2a～2c);最后在碱性条件下分别与N-取代苯基-2-氯乙酰胺发生烷基化反应生成15种未见报道的目标化合物3-(N-取代苯基-2-乙酰胺基)硫基-4-(N-取代邻羟苯基)亚胺基-5-甲基-1,2,4-三唑(3a～3o),其结构经IR,1H NMR,13C NMR确证.初步生物测试表明,质量分数为0.01%时,3a～3o对白色念珠菌的抑菌率均达90%以上,具有很强的抑菌活性;对金黄色葡萄球菌、大肠杆菌的抑菌率达80%以上,具有较强的抑菌活性.     

Synthesis of some new 3-[5-(2-oxo-2H-3-chromenyl)-1,3-oxazol-2-yl]-1,3-thiazolan-4-ones as antimicrobials

<正>A series of some new 2-imino-5-[(Z)-1-(4-methylphenyl)methylidene]-3-[5-(2-oxo-2H-3-chromenyl)-1,3-oxazol-2-yl]-1,3- thiazolan-4-ones 5a-j has been synthesized and assayed for their antibacterial activity against Gram-positive bacteria viz.Bacillus subtilis(ATCC 6633),Staphylococcus aureus(ATCC 6538p) and Micrococcus luteus(IFC 12708),and Gram-negative bacteria viz. Proteus vulgaris(ATCC 3851).Salmonella typhimurium(ATCC 14028) and Escherichia coli(ATCC 25922).Among the screened compounds,5d,5e,5f,5g,and 5j exhibited potent inhibitory activity compared to standard drug,and emerged as potential molecules for further development.     

Microwave promoted synthesis and antimicrobial activity of 3-thiazole substituted 2-styryl-4(3H)-quinazolinone derivatives

The present paper describes an optimized reaction condition for the microwave promoted synthesis of newer 3-thiazole substituted 2-styryl-4(3H)-quinazolinone derivatives, which in turn were prepared in good yield by the treatment of various 2-styryl benzoxazinone derivatives with various 2-aminothiazoles using co-solvent under microwave irradiation. All the compounds were characterized by various spectroscopic techniques and analytical methods. All newly synthesized compounds have been screened for their in vitro antibacterial and antifungal activities against Escherichia coli, Pseudomonas aeruginosa, Bacillus megaterium,Bacillus subtilis, and Aspergillus niger.     

Synthesis of 1-(2-polyfluoroacylaminophenyl)-3-polyfluoroalkylpropane-1,3-diones and 2-polyfluoroalkyl-4-quinolones

The condensation of 2-aminoacetophenone with R^FCO₂Et (R^F = CF₃, CF₂H, CF₂CF₂H) in the presence of LiH in THF or Bu^tOK in Bu^tOH affords either 2-polyfluoroalkyl-4-quinolones or 1-(2-polyfluoroacylaminophenyl)-3-polyfluoroalkylpropane-1,3-diones, depending on the ratio of the initial reactants. The latter are hydrolyzed in an acidic medium to produce 2-polyfluoroalkyl-4-quinolones. N-Methyl-2-trifluoromethyl-4-quinolone was synthesized from 2-aminoacetophenone, CF₃CO₂Et, and MeI in the presence of Bu^tOK.     

Facile synthesis,characterization, and antimicrobial studies of some disubstituted 1,2,3-triazoles with sulfonamide functionality

An expedient synthesis of some 1,4-disubstituted 1,2,3-triazoles (3a–3x) having sulfonamide functionality from various terminal alkynes and aromatic azides through Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition has been reported. The structures of newly synthesized compounds were confirmed by IR, ¹H NMR, ¹³C NMR, high-resolution mass spectra and screened for in vitro antimicrobial activity against Staphylococcus aureus (Gram-positive bacteria), Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes (Gram-negative bacteria), Candida albicans, and Aspergillus niger (fungi). Some of the synthesized compounds were found to exhibit good potency against above-tested microbial strains. Moreover, to study the binding interactions, docking simulation of broadly active compound 3x was also performed against E. coli dihydropteroate synthase enzyme.     

Microwave promoted synthesis of some N-（4-methyl-3-tolylthiazol-2（3H）-ylidene） substituted benzamides

N-(4-Methyl-3-tolylthiazol-2(3H)-ylidene) substituted benzamides(2a-o) were synthesized in good to excellent yields by the base-catalyzed direct cyclization of corresponding 1-tolyl-3-aryl thioureas(1a-o) with 2-bromoacetone through microwave irradiation in a solvent-free medium.Compared to traditional thermal heating,microwave irradiation provides a much more cleaner,efficient and faster method for synthesis of the title compounds.     

One-pot synthesis of 2-trifluoromethyl and 2-difluoromethyl substituted benzo-1,3-diazoles

2-Trifluoromethyl and 2-difluoromethyl substituted benzimidazole, benzoxazole and benzothiazole derivatives were efficiently prepared through a one-pot reaction of trifluoroacetic acid and difluoroacetic acid, respectively, with commercially available o-phenylenediamines, 2-aminophenols, and 2-aminobenzenethiols in good to excellent yields. Subsequential bromination of 2-difluoromethyl groups by photolysis with NBS led to the formation of bromodifluoromethyl benzo-1,3-diazoles which may be utilized to prepare the new generation of gem-difluoromethylene linked identical or non-identical twin molecules for drug synthesis.     

Synthesis and anti-inflammatory and antimicrobial activities of some novel 2-methylquinazolin-4(3H)-one derivatives bearing urea,thiourea and sulphonamide functionalities

A variety of novel 2-methylquinazolin-4(3H)-one derivatives (1–29) bearing urea, thiourea and sulphonamide functionalities at position 3 of biological interest have been synthesized and screened for their anti-inflammatory (TNF-α and IL-6) and antimicrobial activities (antibacterial and antifungal). “Biological evaluation study revealed that the compounds 3, 4, 6, 9, 16 and 18 were found to have promising anti-inflammatory activity (up to 62–84% TNF-α and 73–92% IL-6 inhibitory activity) at concentration of 10 μM with reference to standard dexamethasone (75% TNF-α and 84% IL-6 inhibitory activities at 1 μM) and 7, 10, 12, 23, 25 and 28 have antimicrobial activity at MIC of 10–30 μg/mL against selected pathogenic bacteria and fungi.”     

Synthesis and antimicrobial activity of Schiff bases and 2-azetidinones derived from quinazolin-4(3H)-one

A series of 2-oxo-azetidinyl-quinazolin-4(3H)-ones 5a–k have been synthesized from Schiff bases 4a–k. Schiff bases were synthesized by the condensation reaction of compound 3 with substituted aromatic aldehydes. The benzoxazinone 2 was prepared by the cyclization reaction of acid chloride 1 with 5-bromo anthranilic acid. Further reaction of benzoxazinone 2 with hydrazine hydrate yielded compound 3. The structures of the synthesized compounds were elucidated on the basis of elemental analyses as well as IR and NMR spectral data. Schiff bases 4a–k and 2-azetidinones 5a–k were screened for antibacterial and antifungal activities in vitro. Compounds having chloro and methoxy groups exhibited good antimicrobial activity.     

Synthesis of some substituted benzimidazoles with potential antimicrobial activity

Summary The synthesis andin vitro antimicrobial evaluation of several benzimidazole derivatives with different heterocyclic nuclei at position-2 are described.

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Synthese einiger substituierter Benzimidazole mit potentieller antimikrobieller Aktivität

Zusammenfassung Die Synthese und antimikrobielle Prüfung einiger Benzimidazole mit verschiedenen heterozyklischen Substituenten in 2-Stellung wird beschrieben.

     

相转移催化法合成双3－苯丙烯酰基取代硫脲及双3－苯丙烯酰基取代胺衍生物

以3－苯丙烯酸为原料，经酰氯化，得到3－苯丙烯酰氯，在PEG－400为催化剂 的固液相转移催化条件下与硫氰酸铵及二胺类反应，一锅法制得双3－苯丙烯酰基 取代硫脲化合物。3－苯丙烯酰氯在PEG－600为催化剂的液液相转移催化条件下和 二胺类反应得到双－苯丙烯酰基取代胺化合物。反应条件温和、产率高。化合物经 元素分析、IR及^1H NMR证实。初步的生理活性研究表明，部分化合物具有良好的 抗炎活性。     

Synthesis and antimicrobial activities of some novel substituted 2-imidazolyl-N-(4-oxo-quinazolin-3(4H)-yl)-acetamides

Several substituted-quinazolin-3(4H)-ones 8-11ad were synthesized by condensation of 2-chloro-N-(4-oxo-substituted-quinazolin-3(4H)-yl)-acetamides with various substituted imidazoles through one pot reaction. Elemental analysis, IR, (1)H-NMR and mass spectral data confirmed the structure of the newly synthesized compounds. Synthesized quinazolin-4-one derivatives were investigated for their antitubercular, antibacterial and antifungal activities. Some of the tested compounds showed good antitubercular activity. None of the synthesized compounds showed significant antibacterial and antifungal activity.     

Synthesis of 3-thienyl substituted 2-pyrazolines by 1,3-dipolar cycloaddition

1,3,5-Trisubstituted 3-thienylpyrazolines have been prepared in high yields by the reaction of substituted,N-(P;-nitrophenyl)-3-thiophenecarbohydrazonoyl chlorides with Et₃N in CH₂Cl₂ in the presence of an excess of a monosubstituted olefin. The reaction probably occurs as 1,3-dipolar cycloaddition of the corresponding 3-thiophenecarbonitrile imines formedin situ at the double bond of the olefin.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 114–117, January, 1994.     

Synthesis and characterization of novel fluorinated polyimides derived from 1,3-bis(4-amino-2-trifluoromethylphenoxy)naphthalene and aromatic dianhydrides

A new structurally asymmetric diamine monomer containing flexible ether linkages and bulky trifluoromethyl substituents, namely 1,3-bis(4-amino-2-trifluoromethylphenoxy)naphthalene, was prepared from 1,3-dihydroxynaphthalene and 2-chloro-5-nitrobenzotrifluoride. New series of fluorinated polyimides were synthesized from the diamine with six commercially available aromatic tetracarboxylic dianhydrides using a conventional two-stage process with thermal or chemical imidization. The resulting polyimides were highly soluble in a variety of organic solvents and could afford transparent and tough films via solution casting. These polyimides exhibited moderately high glass-transition temperatures (by DSC) of 236-268 °C and softening temperatures (by thermomechanical analysis) of 231-250 °C, and they did not show significant decomposition before 500 °C under either nitrogen or air atmosphere. Also, they revealed low moisture absorptions (0.32-0.78%), low dielectric constants (2.81-3.24 at 10 kHz), and high optical transparency (ultraviolet-visible absorption cutoff wavelengths of 377-426 nm).