Aromatic Acids In Presence Research Articles

Ru (III) Catalysed Oxidative Degradation of Sodium Bisulphite Derivatives of Aromatic Aldehydes by Potassium Hexacyano Ferrate (III) in Aqueous Alkaline Medium

Introduction: The catalysed oxidation of the derivatives of aromatic aldehydes with inorganic moieties is still unstudied with an economically cheaper oxidant like potassium hexacyanoferrate (III). The catalyst like ruthenium (III) chloride is very much effective at very low concentrations for oxidation reactions. Aims: The study is carried out to observe and to get the results about the oxidative degradation of derivatives of organic and inorganic moieties. Methodology: Benzaldehyde sodium bisulphite (BSS) and substituted aromatic aldehyde sodium bi sulphite like p-chloro benzaldeyde sodium bisulphite, p-methyl benzaldehyde sodium bisulphite, etc. are dissolved in water, can be oxidized in good yield by potassium hexacyanoferrate (III) as PHF in aqueous alkaline medium in presence of ruthenium (III) chloride. Result: The process requires lesser time and probably an intermediate complex of ruthenium (III) chloride, substrate and oxidant give the products. Conclusion: Oxidative degradation of Benzaldehyde sodium bisulfite (BSS) and substituted aromatic aldehyde sodium bisulphite like p-chloro benzaldeyde sodium bisulphite, p-methyl benzaldehyde sodium bisulphite, etc. give moderate to good yield of corresponding aromatic acids in presence of potassium hexacyanoferrate (III) and ruthenium (III) chloride.

Synthesis and Biological Evaluation of Naphthylmethyl-1, 3, 4-Oxadiazoles for Antioxidant and Antibacterial Activities

A Series of 2-((naphthalen-1-yl) methyl)-5-substituted-1,3,4-oxadiazole derivatives were synthesized by refluxing naphthyl acetic acid hydrazide with substituted aromatic acids in presence of phosphorous oxychloride. The intermediate naphthyl acetic acid hydrazide (2) was prepared by treatment of naphthyl acetic acid ester (1) with hydrazine hydrate. The chemical structures of all the twelve synthesized compounds were confirmed by means of IR, 1H NMR and Mass spectral data. All the title compounds were screened for antioxidant activity by Nitric oxide scavenging activity, reduction of DPPH and antibacterial activity using Cup plate method. Among the series of the compounds 4-hydroxy-3,5-dimethoxy (3k), 3-pyridyl (3h), 4-pyridyl (3i) derivatives showed good antioxidant activity in two invitro models. 4-chloro (3b) 4-hydroxy-3,5-dimethoxyderivative(3k), 4-pyridyl (3i) and 3-Pyridyl (3h) derivatives showed good antibacterial activity.

Synthesis, characterization and antimicrobial activity of 1,3,4-oxadiazole bearing 1H-benzimidazole derivatives

2-(Phenoxymethyl)-1H-benzimidazole (3) obtained by acidic condensation of o-phenylene diamine with phenoxyacetic acid, was reacted with ethyl chloroacetate under anhydrous condition to get ethyl [2-(phenoxymethyl)-1H-benzimidazol-1-yl]acetate (4). The ethyl [2-(phenoxymethyl)-1H-benzimidazol-1-yl]acetate (4) on treatment hydrazine hydrate gave 2-[2-(phenoxymethyl)-1Hbenzimidazol-1-yl]acetohydrazide (5). The acid hydrazide group of 5 was cyclocondensed with various aromatic acids in presence of phosphorous oxychloride to get the titled compounds (6a–p). The structures of all the compounds were established on the basis of elemental and spectral analysis. The synthesized compounds were evaluated for their antimicrobial activity. The compound 6d, 6f, 6h and 6d, 6h and 6I a is most active compounds against Escherichia coli and Staphylococcus aureus respectively. The compound 6d, 6f and 6l is most active against Candida albicans and Aspergillus flavus.

SYNTHESIS AND EVALUATION OF SOME SUBSTITUTED ARYL OXADIAZOLE AND MERCAPTO OXADIAZOLE DERIVATIVES FOR ANTIFUNGAL, ANTIMICROBIAL AND ANTITUBERCULAR ACTIVITIES

A number of substituted aryloxadiazoles and mercaptooxadiazoles are known for their biological importance like anti-bacterial, antifungal, anticancer and anti-inflammatory activity. The present investigation is carried out for the synthesis of certain substituted aryloxadiazole and mercaptooxadiazoles and evaluation of their biological activity. The title compounds have been synthesized by reacting isoniazid with substituted aryl aldehydes to give Schiffs bases which on treatment with aromatic acids in presence of phosphorus oxychloride gives aryl oxadiazoles. Mercaptooxadiazoles were synthesized using isoniazid and carbon disulphide. The newly synthesized compounds have been characterized by IR, 1H NMR and CHN analysis. Selected compounds are screened for antimicrobial and antitubercular activity in vitro. Few of them exhibited promising activity.

SYNTHESIS, SPECTRAL CHARACTERIZATION AND ANTIMICROBIAL SCREENING OF SUBSTITUTED 1,3,4-OXADIAZOLE DERIVATIVES

1,3,4-oxadiazoles are important because of its versatile biological actions. In the present study, several 2-(quinoline-8-yloxymethyl)-5-aryl-1,3,4-oxadiazole derivates (IIIa-j) have been synthesized by the condensation of 8-hydroxy quinoline acetyl hydrazide (II) with various aromatic acids in presence of phosphorous oxychloride. The structures of the newly synthesized compounds have been established on the basis of elemental analysis, UV, IR, and 1H NMR spectral data. The synthesized compounds were screened for their in vitro growth-inhibiting activity against different strains of bacteria and fungi viz., S aureus, E. Coli, P. aeruginosa, C. Albicans, A. flavus, and A. fumigates, and the results were compared with the standard such as Ampicillin (50µg/ml) using agar diffusion technique. Compounds IIIc and IIIf were found to be equipotent as ampicillin when tested against the strains of E.Coli where as tested compounds IIIc, IIIf and IIIi showed good antibacterial and antifungal activity when tested against the strains of S. aureus, P. aeruginosa, and C. Albicans.

Synthesis and Antimicrobial Studies on New Substituted 1,3,4-Oxadiazole Derivatives Bearing 6-Bromonaphthalene Moiety

A series of new 1,3,4-oxadiazole derivatives having 6-bromonaphthalene moiety are synthesized.2-[(6-bromo-2-naphthyl)oxy]acetohydrazide was treated with various substituted aromatic acids in presence of POCl3 togive 2-{[(6-bromo-2-naphthyl)oxy]methyl}-5-aryl-1,3,4-oxadiazole. Also the hydrazide on treating with CS2/KOHgave 5-{[(6-bromo-2-naphthyl)oxy]methyl}-1,3,4-oxadiazole-2(3H)-thione, which was subjected to Mannich reactionto get a series of Mannich bases and with alkyl/aryl halide to give2-{[(6-bromo-2-naphthyl)oxy]methyl}-5-[(alkyl/aryl)thio]-1,3,4-oxadiazole. The newly synthesized compounds werecharacterized by analytical and spectral data. Antimicrobial activities of these compounds were carried out and some ofthem have exhibited good activity.

Synthesis and antimicrobial activity of novel naphtho[2,1-b]furo-5H-[3,2-d][1,3,4]thiadiazolo[3,2-a]pyrimidin-5-ones

Ethyl 3-aminonaphtho(2,1-b)furan-2-carboxylate 1 was converted into 3-amino-2- mercaptonaphthofuro(3,2-d)pyrimidin-4(3H)-one 4 by reacting it with carbon disulphide followed by methylation and condensation with hydrazine hydrate. The compound 4 on treatment with aryl isothiocyanates produced 2-arylaminoanilinonaphtho(2,1-b)furo-5H-(3,2- d)(1,3,4)thiadiazolo(3,2-a)pyrimidin-5-ones 5(a-h). The title compounds 6(a-h) were obtained also by reacting 4 with aromatic acids in presence of phosphorus oxychloride. The structures of the newly synthesized compounds were confirmed by IR, 1 H NMR, 13 C NMR and mass spectral studies and elemental analysis. All the synthesized compounds have been screened for antimicrobial activity.

Synthesis of Some New Fluorine Containing 1,3,4‐Oxadiazole Derivatives as Potential Antibacterial and Anticancer Agents.

AbstractFor Abstract see ChemInform Abstract in Full Text.

The reactions of phenols with α,β-unsaturated aromatic acids in presence of polyphosphoric acid : synthetic and mechanistic studies

The reactions of cinnamic acid with phenol itself, catechol, hydroquinone, pyrogallol and 2-naphthol in presence PPA were studied and that with resorcinol was reinvestigated. With phenol itself and hydroquinone were obtained 3,4-dihydro-4-phenylcoumarin (1r) and 6-hydroxy-3,4-dihydro-4-phenylcoumarin (Is), respectively, as the sole products. Catechol and pyrogallol, on the other hand, afforded, besides the corresponding 3,4-dihydrocoumarins, viz. 8-hydroxy-3,4-dihydro-4-phenylcoumarin (It) and 7,8-dihydroxy-3,4-dihydro-4-phenylcoumarin (lu), as the major products, 5,6-dihydroxy-3-phenylindanone (5b) and the chalcone 1-(2',3',4'-trihydroxy)-3-phenylpropan-2-en-1-one (3d), respectively, as minor produets. But contrary to earlier observation, resorcinol was found to give 7-hydroxy-3,4-dihydro-4-phenylcoumarin (Iv) instead of 7-hydroxyflavanone (4e). 2-Naphthol, on the other hand, afforded the chalcone derivative 1-[2'-hydroxynaphthyl]-3-phenylpropan-2-ene-1-one (7) as the exclusive product. The yields of the major products in the above reactions were 50-67% except that with phenol itself yielding Ir in 40% yield. The structures of all the products 1r, Is, It, lu, 1v, 3d, 5b and 7 were established from their various spectral (1R, 1 H and 1 3 C NMR and mass) data. Evidence for plausible mechanisms of formation of the above products was provided.

Derivatives of Salicylic Acid. Part VIII. Interaction of Thionyl Chloride with Esters of Hydroxy Aromatic Acids in Presence of Finely Divided Copper. Part III. Synthesis and Constitution of 3 :3'-Carbomethoxy-4 :4' -hydroxy5 :5' -methyldiphenyl Sulphide and its 6 :6'-Methyl Analogue.

Derivatives of Salicylic Acid. Part VIII. Interaction of Thionyl Chloride with Esters of Hydroxy Aromatic Acids in Presence of Finely Divided Copper. Part III. Synthesis and Constitution of 3 :3'-Carbomethoxy-4 :4' -hydroxy5 :5' -methyldiphenyl Sulphide and its 6 :6'-Methyl Analogue.