Synthesis of 3(5)-aryl-5(3)-pyrazolyl-1,2,4-oxadiazole nitro derivatives

Background: Nitro-derivatives of heterocyclic compounds were used as active agents against pathogenic microorganisms. A set of 4- and 5-nitroimidazole derivatives exhibiting antimicrobial activity was analyzed with the use of Quantitative Structure-Activity Relationships (QSAR) method. The study included compounds used both in documented treatment and those described as experimental. Objective: The purpose of this study was to demonstrate the common and differentiating characteristics of the above-mentioned chemical compounds alike physicochemically as well as pharmacologically based on the quantum chemical calculations and microbiological activity data. Methods: During the study PCA and MLR analysis were performed, as the types of proposed chemometric approach. The semi-empirical and ab initio level of in silico molecular modeling was performed for calculations of molecular descriptors. Results: QSAR models were proposed based on chosen descriptors. The relationship between the nitro-derivatives structure and microbiological activity data was able to class and describe the antimicrobial activity with the use of statistically significant molecular descriptors. Conclusion: The applied chemometric approaches revealed the influential features of the tested structures responsible for the antimicrobial activity of studied nitro-derivatives.

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Regioselectivity of nucleophilic aromatic photosubstitution in the biphenyl series. Photohydrolysis of some dimethoxynitrobiphenyls

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19872482 ◽

1987 ◽

Vol 52 (10) ◽

pp. 2482-2491 ◽

Cited By ~ 1

Author(s):

Ján Urban ◽

Petr Kuzmič ◽

David Šaman ◽

Milan Souček

Keyword(s):

Nitro Group ◽

Steric Hindrance ◽

The Other ◽

Quantum Yields ◽

Hydroxide Anion ◽

Tert Butanol ◽

Nitro Derivatives

Anaerobic photolysis of dimethoxynitrobiphenyls IIIa-VIa in aqueous alkaline tert-butanol gave products of nucleophilic photosubstitution of methoxyl by hydroxide anion, while the dimethoxybiphenyls Ia and IIa were found unreactive. Regioselectivity of the reaction was examined in view of a possible “extended meta activation” by the nitro group. The most reactive substrate IIIa gives both C-3 and C-4 substitution products with an unsubstantial preference for the latter, which opposes the “extended meta selectivity” rule. All of the other compounds obey the rule, and 3,4-dimethoxy-3'-nitrobiphenyl (IVa) even displayed absolute selectivity by yielding C-3 substituted compound as the only product. 2,5-Dimethoxy substituted compounds underwent photosubstitution which much lower quantum yields than their 3,4-substituted counterparts, most probably due to some steric hindrance of conjugation. Similarly, 3-nitro-substituted biphenyls exhibited much lower overall reactivity than 4-nitro derivatives.

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Electrochemical reduction of para-substituted 2-acyl-5-phenylfuranes in dimethylformamide

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19810498 ◽

1981 ◽

Vol 46 (2) ◽

pp. 498-502 ◽

Cited By ~ 4

Author(s):

Jozef Černák ◽

František Tomanovič ◽

Andrej Staško ◽

Anna Fedosyevna Oleinikova ◽

Jaroslav Kováč

Keyword(s):

Electrochemical Reduction ◽

Unpaired Electron ◽

Anion Radical ◽

Electron Wave ◽

Epr Method ◽

Electron Center ◽

Nitrogen Nucleus ◽

Nitro Derivatives ◽

Stable Anion ◽

Derivatives Of

para Substituted chloro, bromo, and nitro derivatives of 2-acyl-5-phenylfurane are reduced polarographically in a one-electron wave to the corresponding anion radicals, which were studied by the EPR method. The reduction of nitro derivatives, studied by the Kalousek switch, is reversible and leads to a stable anion radical with an unpaired electron center on the nitrogen nucleus; the reduction of the halogen derivatives is only partly reversible and leads to unstable ketyl radicals. The bromo derivatives give polarographic maxima typical for concurrent reactions.

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ChemInform Abstract: BROMINATION OF SPIROPYRANS AND REDUCTION OF THEIR NITRO DERIVATIVES

Chemischer Informationsdienst ◽

10.1002/chin.197811206 ◽

1978 ◽

Vol 9 (11) ◽

Author(s):

E. R. ZAKHS ◽

L. A. ZVENIGORODSKAYA ◽

N. G. LESHENYUK ◽

B. P. MARTYNOVA

Keyword(s):

Nitro Derivatives

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Synthesis of 5,7-dihydroxynaphthoquinone derivatives and their reactions with nucleophiles: Nitration of 2,3-dimethylnaphthalene and subsequent transformations

Australian Journal of Chemistry ◽

10.1071/ch9762247 ◽

1976 ◽

Vol 29 (10) ◽

pp. 2247 ◽

Cited By ~ 6

Author(s):

HJ Banks ◽

DW Cameron ◽

MJ Crossley ◽

EL Samuel

Keyword(s):

Unusual Reaction ◽

Nitro Derivatives ◽

Reactions With Nucleophiles ◽

Derivatives Of ◽

Related Compounds ◽

Benzenoid Ring

5,7-Dihydroxy-2,3-dimethyl-l,4-naphthoquinone (5) and related compounds have been synthesized. The quinone affords an accessible substrate for studying an unusual reaction with nucleophiles, which involves attack at the 8-position, i.e. at the benzenoid ring. An unsuccessful approach to (5) has led to tri- and tetra-nitro derivatives of 2,3-dimethylnaphthalene. Reduction of the former and subsequent conversions have given aminonaphthoquinone and perimidinone derivatives.

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Syntheses related to the carbohydrate moiety in lincomycin

Canadian Journal of Chemistry ◽

10.1139/v69-009 ◽

1969 ◽

Vol 47 (1) ◽

pp. 75-79 ◽

Cited By ~ 57

Author(s):

G. B. Howarth ◽

D. G. Lance ◽

W. A. Szarek ◽

J. K. N. Jones

Keyword(s):

Crystalline Form ◽

Carbohydrate Moiety ◽

Allylic Alcohols ◽

Nitro Derivatives ◽

Sugar Derivatives ◽

Cis And Trans

Addition of nitroethane to 1,2:3,4-di-O-isopropylidene-α-D-galacto-hexodialdo-1,5-pyranose (3) gave a mixture of β-nitro alcohols (4), which was acetylated to afford a mixture of β-nitro acetates (5). Dehydroacetylation of the latter gave cis- and trans-6,7,8-trideoxy-1,2:3,4-di-O-isopropylidene-7-C-nitro-α-D-galacto-oct-6-enose (6 and 7) in a ratio of about 6:1, respectively. Addition of ammonia to the cis-nitroolefin (6) gave rapidly a mixture of two stereoisomeric vic-nitroamines (8), which was acetylated to furnish a mixture of two 6-acetamido-6,7-dideoxy-7-C-nitro derivatives (9). The same products (9) were obtained by the action of ammonia in aqueous tetrahydrofuran upon the preponderant β-nitro acetate, followed by acetylation. Vinylation of the aldehyde 3 gave a mixture of allylic alcohols (10); the preponderant epimer was obtained pure in crystalline form. The various 8-carbon sugar derivatives are of interest as potential intermediates in the synthesis of the carbohydrate moiety in lincomycin.

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