Synthesis and antimicrobial evaluation of new 2-pyridinone and 2-iminochromene derivatives containing morpholine moiety

As trail to overcome on the antimicrobial drug-resistance problems, new functionalized 2-pyridinone and 2-iminochromene derivatives bearing morpholine moiety were designed and synthesized. The 2-pyridinone derivatives were obtained through the cyclization of cyanoacetohydrazone of 4-morpholinylacetophenone with 1,3-dicarbonyl compounds, α,β-unsaturated nitriles or 2-(arylidene)malononitriles. The 2-iminochromene derivatives were synthesized through the ring closure of cyanoacetohydrazonewith salicylaldehyde derivatives. The antibacterial and antifungal activities for the synthesized 2-pyridinone and 2-iminochromene derivatives were investigated. Most of the tested compounds showed moderate activity against P. vulgaris. Compounds 4a,b and 5a,b showed moderate activity against G −ve bacteria. All iminochromene derivatives showed moderate activity against C. albicans. Compound 8c was the most active compound.     

Synthesis of some 2,3-Dihydro-11bH-thiazolo[3,2-d][1,4]benzoxazepin-5-(6H)one derivatives. A new heterocyclic ring system

Condensation of (S)-penicillamine methyl or ethyl ester hydrochloride with salicylaldehyde and its C-5 derivatives, provided the diastereomeric thiazolidine derivatives 1 and 2 . The resulting amino function was acylated to afford the amides 3 and 4. Cyclization of the latter led to the 2,3-dihydro-11bH-thiazolo[3,2-d]-[1,4]benzoxazepin-5-(6H)ones 5 and 6. Conformational data for these heterocyclic compounds are discussed.     

Synthesis,Structures, and Fungitoxicity of Novel Organophosphorus Compounds

Abstract

A series of biologically active organophosphorus compounds have been synthesized by the reactions of O,O-diethylchlorophosphate with Schiff bases derived from 5-(phenyl/substituted phenyl)-2-hydrazino-1,3,4-oxadiazole and salicylaldehyde/2-hydroxyacetophenone. The compounds have been characterized on the basis of analyses and spectral (IR, ¹H, ¹³C NMR) data. Fungicidal activities of these derivatives against Colletotrichum falcatum, Fusarium oxysporum, and Curvularia pallescence have been evaluated. All compounds showed moderate to significant antifungal activity.     

Synthesis,antioxidant, and antimicrobial activity of 3-(1H-indole-3-carbonyl)-2H-chromen-2-ones

A simple and convenient method for the one-pot synthesis of 3-(1H-indole-3-carbonyl)-2H-chromen-2-one derivatives from the reaction of 3-cyanoacetyl indole and salicylaldehyde in the presence of Na₂CO₃ in water: methanol (1:1) is described. Wider substrate scope, high yields, operational simplicity, and simple purification process make the protocol highly applicable in the synthesis of 3-(1H-indole-3-carbonyl)-2H-chromen-2-ones. For the first time, in vitro antioxidant and antimicrobial activity was studied. Compounds 5e , 7a , and 7b exhibits good radical scavenging ability against DPPH free radical. Compounds 7b , 5f , and 5g possess lower EC₅₀ values than the Standards AA and BHA and thus proving their high reducing power. Compounds 5d and 5f show good antibacterial activity against gram-positive bacteria (MRSA) while compounds 5c , 7a , and 7b exhibits good antibacterial activity against Bacillus sp. Compounds 5b and 5e show good antibacterial activity against gram negative bacterial strains (Escherichia coli, Klebsiella pneumoniae) and compounds 5g and 5h exhibits good antifungal activity against Candida albicans.     

5-(2-羟基苯基)-3-甲基吡唑酰胺衍生物的合成与杀菌活性

以水杨醛为原料,首次合成了7个5-(2-羟基苯基)-3-甲基吡唑酰胺衍生物,其结构经1H NMR,IR及元素分析表征。初步生物活性测试表明,部分化合物具有一定的杀菌活性。     

Some polyhydroxy azo–azomethine derivatives of salicylaldehyde: Synthesis, characterization, spectroscopic, molecular structure and antimicrobial activity studies

Some new substituted polyhydroxy azo–azomethine compounds were prepared by reaction of tris(hydroxymethyl)aminomethane with (E)-2-hydroxy-5-(phenyldiazenyl) benzaldehyde and its substituted derivatives. The structures of azo and azo–azomethine compounds were determined by IR, UV–vis, ¹H NMR and ¹³C NMR spectroscopic techniques, and/or X-ray diffraction studies. According to IR spectra, all azo–azomethine compounds adopt keto form in solid state. UV–vis analysis has shown the presence of keto–enol tautomerism in solution for all azo–azomethine compounds, except that for nitro substituted derivative, enol form is dominantly favored in solution. At the same time, above mentioned derivative compounds were studied in vitro for their antimicrobial properties. Among the phenylazosalicylaldehyde series compound tested, 4-phenylazosalicylaldehyde, 4-(3-chlorophenylazo)salicylaldehyde, 4-(2-chlorophenylazo)salicylaldehyde, 4-(4-fluorophenylazo)salicylaldehyde, 4-(3-chlorophenylazo)salicylaldehyde and 4-(4-ethylphenylazo)salicylaldehyde showed a weak antimicrobial activity only against gram positive bacteria. On the contrary, phenylazosalicylaldehyde series compounds were reacted tris(hydroxmethyl)aminomethane, that exhibited a strong antimicrobial activity against gram positive bacteria, yeast and mould. Moreover, while the 2-{[1,3-dihydroxy-2-(hydroxymethyl)propan-2-ylimino]methyl}phenol did not show an inhibition on tested microorganism, the addition of phenyldiazine groups to 2-{[1,3-dihydroxy-2-(hydroxymethyl)propan-2-ylimino]methyl}phenol resulted in a strong increases in antimicrobial activity.     

Design,Synthesis, and Antimicrobial Evaluation of some Novel Pyridine,Coumarin, and Thiazole Derivatives

Treatment of 2‐cyano‐N′‐(1‐(pyridin‐2‐yl)ethylidene)acetohydrazide 1 with aromatic/heterocyclic aldehydes 2a–f gave arylidene derivatives 3a–f . Polysubstituted pyridine derivatives 4a,b were prepared either from reaction of arylidene 3a,b with malononitrile or from reaction of acetohydrazide 1 with arylidenemalononitrile 5a,b . Cyclocondensation of acetohydrazide 1 with salicylaldehyde derivatives and acetylacetone furnished pyrido‐coumarins 6,7 and 2‐pyridone‐3‐carbonitrile 8, respectively. In addition, pyrido‐thiazoles 13 and 15 were obtained through reaction of 2‐(1‐(pyridin‐2‐yl)ethylidene)hydrazinecarbothioamide 11 with hydrazonyl chlorides and α‐haloketones, respectively. The structures of synthesized compounds were elucidated with spectral and elemental data. The antimicrobial activity of the synthesized compounds was studied.     

Some fatty acids having an o-heterocycle in their terminal positions. IV. (2-Methyl-2H-chromen-2-yl)acetic acids

(2-Methyl-2H-chromen-2-yl)acetic acid 2a was prepared by condensations of salicylaldehyde with diethyl isopropylidenemalonate followed by hydrolyses. Similarly three methoxy derivatives 2c, 2d , and 2e were also prepared from the corresponding salicylaldehyde.     

Zirconium(IV) Thorium(IV) and Dioxouranium(VI) Complexes of Salicylidene o-Aminobenzothiol

Salicylidene-o-aminobenzothiol and its 5-chloro and 5-bromo derivatives, dibasic tridentate Schiff bases, dervied from the condensation of o-aminothiol and Salicylaldehyde, 5-chloro salicylaldehyde and 5-bromo salicylaldehyde, were used for coordination with Zr(IV), Th(IV) and UO₂(VI) metal inos. The I:I (metal-ligand) stoichiometry of these complexes is shown by elemental analysis and conductometric titrations. Molecular structure of these complexes are proved by Infra-red spectroscopy and thermogravimetric analysis. Magnetic susceptibility measurements of Zr(IV), Th(IV) and UO₂(VI) complexes show their diamagnetic and octahedral geometry. Results show that all the complexes have solvent molecules in coordination with metal ion.     

SCHIFF BASE COMPLEXES OF OXOCATIONS Part II Oxovanadium(IV) complexes with tetradentate optically active Schiff bases

Abstract

The synthesis and properties of oxovanadium(IV) complexes with tetradentate Schiff bases obtained by condensation of two moles of acetylacetone, trifluoroacetylacetone, salicylaldehyde and its 5-chloro and 5-nitro derivatives, with optically active 1,2-diamines, namely (+) propylenediamine, (+) and meso butanediamine, (+) and meso cyclohexanediamine, (-) and meso stilbenediamine, are described. The infrared, circular dichroism and electronic spectra are reported and discussed. The factors influencing the formation of hexacoordinate adducts with donor bases are also discussed.     

Synthesis of Novel (p‐Substituted Styryl) Spirobenzopyrans

A series of (p‐substituted styryl) spirobenzopyrans were synthesized by the Wittig reaction of Fisher's bases with 5‐(p‐substituted styryl) salicylaldehyde derivatives. The final spirobenzopyrans were characterized by the ¹H NMR, IR, UV, and GC‐MS analyses.     

A new diamine containing disiloxane moiety and some derived Schiff bases: synthesis,structural characterisation and antimicrobial activity

A new siloxane diamine, 1,3-bis(amino-phenylene-ester-methylene)tetramethyldisiloxane (1), was obtained by a two-step procedure and used to prepare a series of Schiff bases (2–5), by reaction with different carbonylic compounds: salicylaldehyde, 3,5-dibromosalicylaldehyde, 5-chlorosalicylaldehyde and 3,5-di-tert-butyl-2-hydroxybenzaldehyde. All compounds, separated in crystalline form, were characterised by spectral (FTIR, UV–vis and NMR) analysis as well as by single-crystal X-ray diffraction. In these structures, different packing motifs occur depending on the different association degree determined by intra- and intermolecular π–π stacking interactions. Antimicrobial activity of the compounds was evaluated against three fungi and two bacteria, where the Schiff bases derived from salicylaldehyde and in special 5-chlorosalicylaldehyde showed remarkable activity.     

Salicylaldehyde and dihydroisobenzofuran derivatives from the marine fungus Zopfiella marina

Two salicylaldehyde derivatives (1 and 2), a hydroxymethylphenol (3), five dihydroisobenzofuran (4–8) derivatives, and a 5-chloro-3-deoxyisoochracinic acid (9), together with a known 3-deoxyisoochracinic acid (10) were isolated from the marine fungus Zopfiella marina BCC 18240 (or NBRC 30420). The structures of these compounds were elucidated by extensive spectroscopic analysis. Compound 1 showed weak antituberculous activity against Mycobacterium tuberculosis H37Ra, and antibacterial activity against Bacillus cereus with MIC values of 25 and 12.5 μg/mL, respectively.     

Synthesis and bactericidal activities of novel pyrazole-1-carbothioamide derivatives

4-(2-Hydroxy-phenyl)-but-3-en-2-one (1) was prepared via condensation of salicylaldehyde with acetone, and then reaction of the ketone 1 with thiosemicarbazide was accompanied by cyclization to give substituted pyrazole (2). Seven new 5-(2-hydroxy-phenyl)-3-methyl-4,5-dihydropyrazole-1-carbothioamide derivatives (3a–3g) were synthesized by the acylation of 2 and characterized by means of elemental analysis, infrared (IR), and ¹H nuclear magnetic resonance (NMR). The compounds 3c, 3d, and 3g showed certain bactericidal activity against E. coli; while compound 3g showed certain bactericidal activity against P. vulgaris. Translated from Chinese Journal of Applied Chemistry, 2006, 23(12): 1355–1358 [译自: 应用化学]     

One-pot rapid synthesis of 4H-1-benzopyran derivatives in a deep eutectic solvent

A method for introducing a biologically active heterocycle, 2-methylquinoline into the 4-position of a 2-amino-4H-1-benzopyran skeleton is described. Choline chloride/glucose (1:1 molar ratio) was used as both the solvent and catalyst in the reaction of a salicylaldehyde, methylquinoline, and cyanoacetate to obtain 2-amino-4H-1-benzopyran derivatives in 48%–80% yields after short reaction times. The effects of the deep eutectic solvent type, substrate molar ratio, cosolvent, temperature, and reaction time were examined. The method has the advantages of simple steps, environmental friendliness, mild conditions, and wide substrate applicability. This is the first attempt to synthesize methylquinoline derivatives of 4H-1-benzopyran.     

Products of the condensation of 5-nitro- and 5,6-dinitro-1,2,3-trimethylbenzimidazolium salts with o-hydroxyaldehydes

The corresponding 2-(o-hydroxystyryl)benzimidazoles were obtained by the condensation of aromatic o-hydroxyaldehydes with 5-nitro- and 5,6-dinitro-1,2,3-trimethylbenzimidazolium salts. It was established that derivatives of salicylaldehyde and 5-methoxysalicylaldehyde are capable of intramolecular cyclization in absolute, aprotic solvents to form spiro (benzimidazoline-2,2-[2H]chromene) derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 961–966, July, 1971.     

Synthesis and spectroscopic and electrochemical studies of chitosan Schiff base derivatives

Schiff derivatives were prepared by the reactions of salicylaldehyde and its derivatives (5-chloro, 5-methoxy, 5-fluoro, 5-methyl, 5-nitro) with the amino group of chitosan. The Schiff bases were studied by Fourier IR spectroscopy and by UV-visible spectroscopy. The cyclic voltammograms of the Schiff bases were analyzed and compared to those of chitosan and salicylaldehyde. The formal potential of the chitosan Schiff base derivative correlates with the Hammett parameters. The oxidation potential increases and the optical density decreases with enhancement of the electron-acceptor properties of the functional group R in the m-position to the -N=CH-group. Chitosan (Chi) is a polysaccharide whose chains consist of recurrent units of acetamido-2-deoxy-D-glucode linked by the 1,4-β-glycoside bond. This polysaccharide was widely studied as drug carrier [1, 2], because it is nontoxic, biodegradable, and well biocompatible [3].     

Zinc(II) Complexes with Azomethines of 2,4,6-Trimethylaniline and Halogen-Substituted Salicylaldehyde

Russian Journal of General Chemistry - Azomethines were synthesized from 2,4,6-trimethylaniline, salicylaldehyde, and its 3(5)-halogen derivatives, as well as their complexes with zinc(II) (ZnL2)....     

Synthesis of 3‐Aryl‐5‐t‐butylsalicylaldehydes and their Chiral Schiff Base Compounds

Six meta‐substituted salicylaldehyde compounds have been prepared in 68–90% yields by the Suzuki–Miyaura coupling reaction using 3‐bromo‐5‐t‐butylsalicylaldehyde (1a) and arylboronic acids (2a–f) as reactants. Among the obtained products, 3‐(4‐fluorophenyl)‐5‐t‐butylsalicylaldehyde (3b), 3‐(4‐methylphenyl)‐5‐t‐butylsalicylaldehyde (3d), 3‐(1‐naphthyl)‐5‐t‐butylsalicylaldehyde (3e), and 3‐(2‐naphthyl)‐5‐t‐butylsalicylaldehyde (3f) have not been reported so far. A series of new Schiff base ligands (L1–L10) were obtained in 51–89% yields from these salicylaldehyde derivatives.     

Synthesis of hexa-, tetra-, and dihydroxanthene derivatives from salicylaldehyde aminals

Salicylaldehyde aminals react with cyclohexanone upon heating to form tetrahydroxanthene derivatives. The structure of one of these derivatives,viz., 5,7-dichloro-4a-morpholino-1,2,3,4-tetrahydro-4aH-xanthene, was established by X-ray diffraction analysis. The scheme of the reaction was suggested, which involves cycloaddition of intermediateo-methylenequinone (from aminal) and enamine (from cyclohexanone). The reactions of salicylaldehyde aminals with enamines that formed from cyclohexanone can successively afford derivatives of hexahydroxanthene, tetrahydroxanthene, and dihydroxanthene. Procedures were developed for the synthesis of these compounds.N-Substituted 4a-amino-7-nitro-1,2,3,4-tetrahydro-4aH-xanthenes were also prepared by the reactions of dialkylammonium 2-formyl-4-nitrophenoxides with the above-mentioned enamines. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 959–965, May, 1999.