Search

1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) was used as a mild and efficient catalyst for synthesis of various dihydropyrano[3,2-c]chromene-3-carboxylate derivatives via one-pot, three-component condensation of aromatic aldehydes, active methylene and 4-hydroxycoumarin in ethanol under reflux. The distinctive features of this process are mild reaction conditions, reusability of the reaction media, short reaction time, easy isolation of products and good yield. In addition, the effect of electron donating and withdrawing groups on the reactivity of chromene derivatives was investigated and evaluated by quantum chemical tools. For this purpose, the FMO analyses were performed and considered in terms of the new perspectives of the C-DFT. Also, the NBO analyses of the chromene derivatives were conducted to look for and compare the resonance and inductive effect on the possible reactivity behaviors. [ABSTRACT FROM AUTHOR]

Hydroxymethylfurfural (HMF) derivatives that contain an acrylonitrile group result in interesting scaffold molecules that can be obtained from biomass. However, the synthesis of these types of molecules has not been extensively studied. In this study, we investigated the catalytic activity of Mg(OH)2 and MgO materials. Specifically, we evaluated the Knoevenagel reaction between HMF and malononitrile as a test reaction under solvent-free conditions. The fresh and used catalysts were evaluated using various techniques. Our results indicate that the combination of synthesis methods influences the crystalline, basic, and textural properties of the catalysts. We found that water plays an essential role in obtaining high yields. By using this simple and inexpensive method, we were able to achieve yields near 90% in short reaction times ($

• Novel series of bis azo dyes 3–10 were synthesized via a two-step process. • The disperse azo were synthesized and characterized by UV–visible, FT-IR and NMR. • The electronic absorption properties were investigated experimentally and computationally. • Significantly improved fastness properties of the new disperse dyes for the PET fabrics were observed. • The color strengths (K/S) and CIE Lab* color space indicate high efficiency of disperse dyes on polyester fiber. In this study, a novel series of bis-azo dyes 3–10 were synthesized via a two-step process. Initially, benzene-1,4-bis(diazonium) chloride was reacted with several active methylene compounds, such as ethyl acetoacetate, acetyl acetone, ethyl cyanoacetate, and malononitrile. yielding the corresponding bis-azo dyes 3–6. Subsequently, these dyes were cyclized through condensation with phenylhydrazine, resulting in the formation of bis-pyrazole derivatives 7–10. Comprehensive spectroscopic characterization, employing techniques like infrared (IR), nuclear magnetic resonance (NMR), and ultraviolet-visible (UV–Vis) spectroscopy, along with elemental analysis, elucidated the structural features, and electronic transitions of the synthesized dyes. The electronic absorption properties were investigated experimentally and computationally, revealing bathochromic and hypsochromic shifts influenced by substituents and tautomeric forms. The dyes showcased excellent dyeing performance on polyester fabrics, exhibiting notable color strength, perspiration fastness, light fastness, and wash fastness. Theoretical investigations of the electronic properties were conducted utilizing Density Functional Theory (DFT) methodology, employing the B3LYP functional with the 6–31G(d,p) basis set, enabling a comprehensive understanding of the structure-performance relationships governing the dyeing behavior of these dyes on polyester. [Display omitted] [ABSTRACT FROM AUTHOR]

A new series of chromeno[4,3-b]pyridine derivatives has been designed, synthesized via reaction of 4-amino-2-oxo-2H-chromene-3-carboxaldehyde (1) with activated methylene compounds as (3-acetyl-2H-chromen-2-one, 1-(10H-phenothiazin-2-yl)ethan-1-one 2-(1H-benzo[d]imidazol-2-yl)acetonitrile, quincilidin-3-one hydrochloride, 2-oxo-3-phenylpropanoic acid, thiazolidine-2,4-dione, 1,2-iminothiazolidin-4-one, 1,3-diphenylimidazolidine-2,4-dione,2-methyl-2-phenyl-1,3-oxothiazolan-5-one). These compounds were screened for computational ADME and Lipinski's analysis followed by molecular docking and binding energy. The anticancer activities of the synthesized compounds were studied in breast (MCF-7). The molecular docking studies were found the oxolone moiety is a required common feature for good interaction and we found that compounds 2a, 2b, and 3 showed the highest activity toward breast cancer cell line. The structures of the new synthesized compounds were confirmed by 1H-NMR, 13C-NMR, IR, and MS spectroscopic methods. [ABSTRACT FROM AUTHOR]

Pyrano[3,2-b]pyrans are an important class of heterocyclic compound containing fused 4H-pyrans rings that are a structural constituent of many natural, non-natural, drug candidates, synthetic compounds and plays a significant role in the field of medicinal and pharmaceutical chemistry because of their wide-ranging biological activities. The natural γ-pyrone, 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one, popularly known as kojic acid have emerged as the most effective substrates for the synthesis of several useful dihydropyrano[3,2-b]pyrans and their corresponding spiro-pyrano[3,2-b]pyran derivatives. Furthermore, the attractiveness of 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one and its derivatives has drastically increased over the past decades due to their vast applications in medicinal chemistry, food industry, cosmetic products, and chemical industry. Benefited from the diversity and application in various fields of the starting materials, an extensive array of synthetic strategies for the construction of dihydropyrano[3,2-b]pyrans and spiro-pyrano[3,2-b]pyran derivatives has been developed successfully over the last decades. This review will summarize all the synthetic strategies developed for the construction of dihydropyrano[3,2-b]pyran and spiro-pyrano[3,2-b]pyrans using the reactivity of 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one from 1997 to 2020 and focused on their medicinal application. In order to furnish a complete and understandable overview, this review article is organized based on the nature of the catalyst employed. [ABSTRACT FROM AUTHOR]

Herein, a distinctive dihydroxy ionic liquid ([Py-2OH]OAc) was straightforwardly assembled from the sonication of pyridine with 2-chloropropane-1,3-diol by employing sodium acetate as an ion exchanger. The efficiency of the ([Py-2OH]OAc as a promoter for the sono-synthesis of a novel library of condensed products through DABCO-catalyzed Knoevenagel condensation process of adequate active cyclic methylenes and ninhydrin was next investigated using ultimate greener conditions. All of the reactions studied went cleanly and smoothly, and the resulting Knoevenagel condensation compounds were recovered in high yields without detecting the aldol intermediates in the end products. Compared to traditional strategies, the suggested approach has numerous advantages including mild reaction conditions with no by-products, eco-friendly solvent, outstanding performance in many green metrics, and usability in gram-scale synthesis. The reusability of the ionic liquid was also studied, with an overall retrieved yield of around 97% for seven consecutive runs without any substantial reduction in the performance. The novel obtained compounds were further assessed for their in vitro antitumor potential toward three human tumor cell lines: Colo-205 (colon cancer), MCF-7 (breast cancer), and A549 (lung cancer) by employing the MTT assay, and the findings were evaluated with the reference Doxorubicin. The results demonstrated that the majority of the developed products had potent activities at very low doses. Compounds comprising rhodanine (5) or chromane (12) moieties exhibited the most promising cytotoxic effects toward three cell lines, particularly rhodanine carboxylic acid derivative (5c), showing superior cytotoxic effects against the investigated cell lines compared to the reference drug. Furthermore, automated docking simulation studies were also performed to support the results obtained. [ABSTRACT FROM AUTHOR]

We have developed the use of Bronsted acid for Knoevenagel condensation. Sulfated polyborate has been used for efficient Knoevenagel condensation of aromatic, heterocyclic, α,β-unsaturated, and aliphatic aldehydes in the ecologically friendly ethanol: water (1:1) mixture as solvent at 70 °C. It took less time for certain aldehydes to react with active methylenes. The present method demonstrated significant benefits in terms of first-time use of Bronsted acid catalyst, mild reaction conditions, and better product yields.

Common and novel synthesized active methylene compounds as well as heterocycles bearing active methyl or having an active methine were used in the syntheses of a wide variety of substituted and fused five-, six- and seven-membered nitrogenous heterocyclic systems of interesting medical and pharmaceutical importance such as triazoles, pyridazines, triazines, and diazepines. Carbothiosemicarbazides, carbothiohydrazones and 2-hydrazinoazaherterocycles were used as suitable starting materials for triazole formation. The preparation of tetrazoles showed a valence ring-chain tautomerism. The key starting materials for the synthesis of pyridazines were acetohydrazide derivative, activated enones, enaminones, and aryl hydrazones. The reaction of 2-chloro or 2-hydrazinoazaheterocycles and thiocarbohydrazones with different reagents under suitable reaction conditions led to the formation of triazines. Diazepines were obtained via treatment of enones with 1,2-diamino derivatives. Also, the antimicrobial activities of some selected synthesized heterocyclic compounds were reported. [ABSTRACT FROM AUTHOR]

Common and novel synthesized active methylene compounds as well as heterocycles having active methyl or active methine sites have been used for the synthesis of a wide variety of substituted pyrimidines and pyrimidopyrimidines of interesting medical and pharmaceutical importance. Many synthetic approaches were used for the preparation of target heterocyclic systems such as cyclocondensation reactions, ring-opening ring-closure, cycloaddition, acid-, base-catalyzed reaction, intramolecular cyclization and self-condensation has been reported in this part. Also, three different biological applications namely, antimicrobial activity, cellobiase activity and mollucicidal activities was carried out on some reported pyrimidines and pyrimidopyrimidines. [ABSTRACT FROM AUTHOR]

Biologically privileged fused pyrimidine spirocycles were synthesized via a metal‐free three‐component cascade reaction utilizing mercapto/aza lactam active methylene compounds. This rapid and efficient one‐pot operation quickly delivered seven different polycyclic and spirocyclic scaffolds such as pyranothiazolopyrimidine, benzothiazolopyranopyrimidine, pyranotriazolopyrimidine, benzoimidazolopyranopyrimidine, spiroindolinepyranothiazolopyrimidine, spirobenzothiazolopyranopyrimidineindoline, and spirobenzo‐imidazolopyranopyrimidineindoline at room temperature with excellent regio/chemoselectivity. [ABSTRACT FROM AUTHOR]

In the present study, we report the synthesis of different condensed pyrimidine derivatives by the exploitation of addition reactions to π-deficient systems or active methylene building blocks. For instance, the Diels-Alder reaction of pyrimidinethione 1 and benzalacetophenone 2 yielded pyridopyrimidine 5 (Scheme 1). On the other hand, the Michael addition of active methylene containing compounds to 1 produced derivatives 8, 10, 11, 12 and 14 (Scheme 2). The alkylation of 1 by ethylchloroacetate yielded 16. Furthermore, a triazinoquinazoline 19 was obtained through the cyclic condensation reaction of 1 with benzilmonohydrazone (Scheme 3). All reactions proceeded in good to moderate yields and the resulting compounds were characterized by different spectroscopic techniques.The synthesis of 5 by heterocyclization of pyrimidinethione 1 and benzalacetophenone 2Synthesis of quinazoline derivatives 8, 10, 11, 12 and 14 [ABSTRACT FROM AUTHOR]

Abstract: The C−C bond formation between active methylene compounds and allylic alcohols has been newly developed by using a palladium complex as a catalyst together with a phosphine‐borane ligand. The best phosphine‐borane ligand for this direct allylation has been revealed to be Ph2P(CH2)4(9‐BBN) to produce a variety of desirable allylated products in high yields. [ABSTRACT FROM AUTHOR]

The reaction of 5-halogenouracil and uridine derivatives 1 and 7 with active methylene compounds under basic conditions produced diverse and selective C-C bond formation products by virtue of the nature of the carbanions. Three different types of reactions such as the regioselective C-C bond formation at the 5- and 6-positions of uracil and uridine derivatives (products 2, 5, 8, 17, 20 and 21), and the formation of fused heterocycle derivatives 2,4-diazabicyclo[4.1.0]heptane (15) and 2,4-diazabicyclo-[4.1.0]nonane (16) via dual C-C bond formations at both the 5- and 6-positions were due to the different active methylene compounds used as reagents.

Condensation of 3-acetyl-8-ethoxycoumarin (3) with thiosemicarbazide gave ethylidenehydrazinecarbothioamide 5, which was transformed into the thiazolidin-4-one derivatives 6,7. Interaction of 3 with DMF/POCl3 gave b-chloroacroline derivative 8. Treatment of 3 with malononitrile gave benzo[c]chromone and 2-aminobenzonitrile derivatives 9 and 10, respectively with respect to the reaction conditions. Condensation of 3-(2-bromoacetyl)-8-ethoxycoumarin (4) with o-phenylenediamine gave 3-(quioxaline-2-yl)-8-ethoxycoumarin hydrobromide (11), while 4 reacted with 2-aminopyridine to give chromenopyridopyrimidine derivative 12. Condensation of 4 with potassium thio-cyanate/methanol gave an unexpected derivative, 2H-chromeno-3-carboxy(methyl-carbonimidic)thioanhydride 16, which upon treatment with (NH2)2·H2O gave 3-ethoxy-2-hydroxybenzaldehyde azine 19. Interaction of 4 with thiourea derivatives gave thiazole derivatives 20a–c. The structures of the newly synthesized compounds were confirmed by their spectra data. The newly synthesized compounds were also screened for their antimicrobial activity.

The reaction of methyl ketones 1a-g with dimethylformamide dimethylacetal (DMFDMA) afforded the enaminones 2a-g, which were coupled with diazotized aromatic amines 3a,b to give the corresponding aryl hydrazones 6a-h. Condensation of compounds 6a-h with some aromatic heterocyclic amines afforded iminoarylhydrazones 9a-m. Enaminoazo compounds 12a,b could be obtained from condensation of 6c with secondary amines. The reaction of 6e,h with benzotriazolylacetone yielded 14a,b. Also, the reaction of 6a,b,d-f,h with glycine and hippuric acid in acetic anhydride afforded pyridazinone derivatives 17a-f. Synthesis of pyridazine carboxylic acid derivatives 22a,b from the reaction of 6b,e with dimethyl acetylenedicarboxylate (DMAD) in the presence of triphenylphosphine at room temperature is also reported. Most of these reactions were conducted under irradiation in a microwave oven in the absence of solvent in an attempt to improve the product yields and to reduce the reaction times.

The present work addresses a development of metal free one pot direct method for sulfenylation of active methylene compounds and indole. The reaction might proceed through sulfenyl bromide as an intermediate, which initiates the C–S bond formation. The reaction was performed using tetrabutylammonium tribromide (TBATB) as a brominating agent, CH 2 Cl 2 as a solvent at room temperature. [ABSTRACT FROM AUTHOR]

Indoor air pollution is caused inevitably due to complicated home decoration, in which formaldehyde is one of the most typical pollutants. It will be a convenient, economical and effective strategy to remove indoor formaldehyde if imparting a feature of formaldehyde removal to decorative coatings. We have successfully explored a novel silicone-based polymer containing active methylene used as a formaldehyde absorbent in coatings via a straightforward transesterification process using inexpensive and easily available chemicals. The polymer has been characterized by 13 C NMR, FTIR, GC and GPC. Formaldehyde removal capacity of the coating films containing different contents of the polymer has been investigated. The results indicated that coatings incorporating 4 wt% of the polymer could make the coating films exhibit significant improvement on formaldehyde removal including purificatory performance (>85%) and durability of purificatory effect (>60%), compared to those consisting of absorbents without any silicon, and improve yellowing resistance performance, while other properties, such as gloss, adhesion, pencil hardness, flexibility and impact resistance, were kept almost unaffected. The chemical absorption process of the silicone-based polymer filled in interior decorative coatings is demonstrated as a promising technology to purify indoor formaldehyde and thus can reduce the harm to individuals. [ABSTRACT FROM AUTHOR]

A series of new oxygen-, nitrogen- and sulfur- containing spiro heterocycles was synthesized by reactions of 2-(3-hydroxy-5,5-dimethylcyclohex-2-enylidene)malononitrile with some active methylene and bidentate compounds. [ABSTRACT FROM PUBLISHER]

The reaction of 5-halogenouracil and uridine derivatives 1 and 7 with active methylene compounds under basic conditions produced diverse and selective C-C bond formation products by virtue of the nature of the carbanions. Three different types of reactions such as the regioselective C-C bond formation at the 5- and 6-positions of uracil and uridine derivatives (products 2, 5, 8, 17, 20 and 21), and the formation of fused heterocycle derivatives 2,4-diazabicyclo[4.1.0]heptane (15) and 2,4-diazabicyclo- [4.1.0]nonane (16) via dual C-C bond formations at both the 5- and 6-positions were due to the different active methylene compounds used as reagents. [ABSTRACT FROM AUTHOR]

Condensation of 3-acetyl-8-ethoxycoumarin (3) with thiosemicarbazide gave ethylidenehydrazinecarbothioamide 5, which was transformed into the thiazolidin-4-one derivatives 6,7. Interaction of 3 with DMF/POCl3 gave β-chloroacroline derivative 8. Treatment of 3 with malononitrile gave benzo[c]chromone and 2-aminobenzonitrile derivatives 9 and 10, respectively with respect to the reaction conditions. Condensation of 3-(2-bromoacetyl)-8-ethoxycoumarin (4) with o-phenylenediamine gave 3-(quioxaline-2-yl)-8-ethoxycoumarin hydrobromide (11), while 4 reacted with 2-aminopyridine to give chromenopyridopyrimidine derivative 12. Condensation of 4 with potassium thio-cyanate/methanol gave an unexpected derivative, 2H-chromeno-3-carboxy(methyl-carbonimidic)thioanhydride 16, which upon treatment with (NH2)2·H2O gave 3-ethoxy-2-hydroxybenzaldehyde azine 19. Interaction of 4 with thiourea derivatives gave thiazole derivatives 20a-c. The structures of the newly synthesized compounds were confirmed by their spectra data. The newly synthesized compounds were also screened for their antimicrobial activity. [ABSTRACT FROM AUTHOR]

Benzo[b][1,5]thiazepines 1a or 1b were prepared via reaction of o-aminothiophenol with 3-(bis(methylthio)methylene)-pentane-2,4-dione or 2-(bis(methylthio)methylene)-3-carbonitrile, respectively. Reaction of compound 1a with malononitrile afforded pyrano[4,3-b]benzothiazepine 2a, which underwent cyclization into pyrido[4,3-b][1,5]benzothiazepine 2b. Also, reaction of compound 1a with ethyl cyanoacetate afforded pyrano[4,3-b][1,5]benzothiazepin-3-one 3. Reaction of compound 1a with hydrazine, phenylhydrazine, or hydroxylamine afforded the corresponding azolobenzothiazepines, 4-6, respectively. Reaction of compound 1a with ethylenediamine afforded 1,5-benzothiazepin-ethanone 7, which underwent cyclization to [1,4]diazepino[5,6-b][1,5]benzothiazepine 8. Also, compound 1b was reacted with acetylacetone or ethyl acetoacetate to afford pyrano[4,3-b][1,5]benzothiazepines 9a or 9b, which reacted with ammonium acetate to give pyrano[4,3-b][1,5]-benzothiazepine 10a or pyrido[4,3-b][1,5]-benzothiazepine 10b, respectively. Compound 1b was allowed to react with hydrazine, phenylhydrazine, or hydroxyl amine to afford pyrazolo or isoxazolo[3,4-b][1,5]benzothiazepines 11, 12, or 13, respectively. [ABSTRACT FROM AUTHOR]

Ketene N,S-acetal potassium salts (2a-g), prepared via reaction of active methylenes (1a-g) with phenyl isothiocyanate in the presence of potassium hydroxide, were allowed to react with ethyl chloroacetate or chloroacetamide to afford the corresponding 2-ylidene-4-thiazolidinones (3a-g) in good yields. Compounds (3a-g) reacted with a variety of aromatic aldehydes to afford the corresponding 5-arylidene-2-ylidene-4-thiazolidinone derivatives (10a-e). Reaction of compound (3a) with triethylorthoformate afforded 5-ethoxymethylene-2-ylidene-4-thiazolidinone derivative (7), which was allowed to react with ammonia or phenyl hydrazine to give the corresponding enamino or hydrazino derivatives (8a) or (8b), respectively. [ABSTRACT FROM AUTHOR]

Abstract: The indium(III) triflate mediated addition of active methylene compounds to terminal alkynes has been expanded to use malonates and low boiling terminal alkynes to form the Markovnikov addition products. Indium(III) chloride and indium(III) bromide were also found to be efficient catalysts. Knoevenagel condensation products were isolated when reactions involved a simple malonate or β-ketoester. [Copyright &y& Elsevier]

The condensation reactions of formylferrocene with active methylene- containing compounds were achieved by microwave irradiation, grinding or heating in water, in moderate to good yields. The structures were confirmed by 1H NMR, 13C NMR, IR spectra, and elemental analyses. [ABSTRACT FROM AUTHOR]

Electrophilic olefins were synthesized in solvent‐free condition using DMAP (10%mol) as catalyst in excellent yield and E‐geometry. The various aldehydes which are aliphatic, aromatic, and heterocyclics underwent smoothly for Knoevenagel condensation with different active methylene compounds. #IICT Communication No. 030900. [ABSTRACT FROM AUTHOR]

Studies on bromination of active methylene with a mixture of hydrogen peroxide or tert-butylhydroperoxide (TBHP) and hydrobromic acid are discussed. Substituted acetophenones, benzocyclic ketones provide α-bromo-keto compounds in high yields under this reaction condition. [ABSTRACT FROM AUTHOR]

3-Dimethyl-1-[3-methyl-(4H)-5-phenylimidazol[2,1-b]thiazol-2-yl]prop-2-enone 4 couples smoothly with benzenediazonium chloride to yield propanal 5 which is a key intermediate for the synthesis of pyridazinones 9–13, 16 and pyridazine-6-imine 8, 19. Pentadienonitrile 18 was converted into pyridine-3-carbonitrile 20 on refluxing in ethanolic sodium ethoxide solution. Pyrazole 24 was synthesized from the reaction of 5 with 1-chloro-2-phenylhydrazono propan-2-one 22. [ABSTRACT FROM AUTHOR]

A series of bis azo disperse dyes were synthesized starting from benzidine and four couplers contain active methylene group, namely; thiobarbituric acid, barbituric acid, dimedone and thiohydantoin, to give 3 a-c and 4 , respectively. The dye products were identified by UV–visible, FT-IR, 1H NMR and 13C NMR spectroscopy. The electronic absorptions of the synthesized dyes indicated that the λ max are slightly dependent on the coupler moieties and quite sensitive to pH change. Dyeing of polyester yarn(PE-Y) was done in DMF, whereas, polyester fabric (PE-F) was dyed in water using dispersing agent DYEWELL-002. Fastness properties of bis azo dyes 3a-c and 4 on PE-F are better than those of PE-Y. The summation of color strength (K/Ssum) values of PE-F followed the order 3c > 4 > 3a > 3b. The DFT method was used to calculate the chemical descriptor parameters of the protonated form of bis azo dyes 3a-c and 4 , using B3LYP/6-31G(d,p) level for investigation of dyeing efficiencies as well as to predict the mechanism of dyeing process. The computed results point out that dye 3a has the highest dyeing strength based on E HOMO , E LUMO , ΔE, η and S parameters while dye 4 is the highest depending on χ and μ eV parameters. The correlation results of the computed parameter with color strength (K/S) and Exhaustion (%E) in case of PE-Y indicated that they depend mainly on the effect of electronegativity χ with correlation coefficient 0.993 and 0.877, respectively. In a similar way, the PE-F exhibits very good effect of color strength with dipole moment (R2 = 0.899). The protonated dyes 3a-c and 4 can adsorbed on the PE surface either by hydrogen bond or/and electrostatic attraction. [Display omitted] • A series of bisazo dyes were synthesized as a disperse dyes. • The electronic absorptions of the synthesized dyes slightly dependent on the coupler moieties and quite sensitive to pH change. • The fastness properties of the new disperse dyes for the polyester fabrics were Significantly improved. • The mechanism of dyeing polyester fiber with bisazo dyes was discussed. • The computational results of absorptions of bisazo disperse dyes are compared with the experimental ones. [ABSTRACT FROM AUTHOR]

• Azo compounds have broad range applications • Synthesis of azo compounds via diazotization • Synthesis of azo compounds via Mill's reaction • Solvent free Synthesis of azo compounds Azo compounds are important class of compounds and have verstile applications in various fields of life. Because of their broad range of applications, it is necessary to have versatile methods of synthesis to have new azo derivatives in good yields. This review covers the synthetic methodology with emphasis on the classical and versatile ones. The overall feasible methods for azo compounds synthesis mentioned in this review includes, diazotization/azo coupling, solvent free-silica supported boron trifluoride, methyl nitrite-active iron based-Japp-Kalingemann, Novartis/Ciba-Geigy-Cupric chloride catalyzed-Mild one-pot two step-nitroamatics and anilines-deoxygenation of nitrobenzene-decomposition of N,N, Ortho para benzoquinonediimines dioxide dehydrogenation, arylhydrazines dimerization reaction of diazonium salts-metal catalyzed coupling, Opening of benzotriazoles-Oxidation of anilines-arylcalcium and nitrous oxide-quinone acetals and arylhydrazines-quinones, reduction of azoxybenzenes and azo-MOFs, etc, which yield azo compounds in good to moderate yields. The most widely used methods to synthesize azo compounds are by Mills reaction and azo coupling which are important in industrial point of view and are extensively used worldwide. Though there are various reported methods to get azo compounds but they have limitations as well. Therefore there is still a need to have latest and efficient methods keeping in view the advantages and disadvantages of above mentioned methods in order to have innovative and more efficient method for synthesis of azo compounds. [ABSTRACT FROM AUTHOR]

Summary: In this study, In Vitro antibacterial and antifungal activities of azo series based on transition metal complexes (Cu2+, Zn2+, Mn2+, Co2+ and Ni2+) with already our reported ligands named as; [(E)-1-(1, 3-dioxolan-2-yl)-2-phenyldiazene] (K-1), [(E)-1-(1, 3-dioxolan-2-yl)-2-(4-methylphenyl)diazene] (K-2), 2-[(E)-phenyl diazenyl]-1H-benzimidazole] (K-3), [(E)-1-(1, 3-dioxolan-2-yl)-2-(4-ethylphenyl)diazene] (K-4), and [(E)-1-(1, 3-dioxolan-2-yl)-2-(2-methylphenyl)-diazene] (K-5) were studied. FTIR 1H-NMR and mass spectrometric techniques were applied for interpretation of synthesized complexes. 4.05-4.07 ppm chemical shift appearance of azo group confirms azo coupling with transition metal complexes. N=N, C-H, C-N and C-O groups are also confirmed by FTIR which exhibited peaks at 1400-1500, 2090-3090, 1100-1180, 1010-1060 and 625-780 cm-1. Furthermore, mass spectroscopic data also gives strong indication for the synthesis of metal complexes. All the newly synthesized complexes were screened for their antibacterial and antifungal activities. Antibacterial and antifungal activity against S. aureus, E.coli and A.niger, A.ustus and C.albican at conc. 250 µg/ml showed excellent activity by K-1 complexes (Co2+, Cu2+, Ni2+), K-5 complexes (Zn2+, Mn2+, Cu2+), K-2 complexes (Co2+, Cu2+, Mn2+) and K-3 (Zn2+, Mn2+, Co2+, Cu2+) as compared to standard drug (Ampicillin). Hence, based on this study, it was concluded that these azo based complexes may act as a platform for designing more active antibacterial and antifungal agents. [ABSTRACT FROM AUTHOR]