Acyl hydrazines as precursors to acyl radicals

Braslau, Rebecca; Anderson, Marc O.; Rivera, Frank; Jimenez, Armando; Haddad, Terra D.; Axon, Jonathan R.

doi:10.1016/s0040-4020(02)00490-8

Cited by 67 publications

(33 citation statements)

References 61 publications

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“…Furthermore, if the reaction wound have gone through free radical intermediates, formation of acyloxyamine addition product would be expected in the presence of the radical trapper TEMPO (2,2,6,6‐tetramethylpiperidinyloxy, a stable nitroxyl radical). The absence of any acyloxyamine addition product in the reaction mixture in the presence of TEMPO may confirm the absence of the isonicotinoyl radical in the reaction process .…”

Section: Resultsmentioning

confidence: 90%

Oxidation of Antitubercular Drug Isoniazid by a Lipopathic Oxidant, Cetyltrimethylammonium Dichromate: A Mechanistic Study

Garnayak

Patel

2015

Int. J. Chem. Kinet.

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The oxidation of an antitubercular drug isoniazid by a lipopathic oxidant cetyltrimethylammonium dichromate (CTADC) in a nonpolar medium generates isonicotinic acid both in the presence and the absence of acetic acid. The conventional UV–vis spectrophotometric method is used to study the reaction kinetics. The occurrence of the Michaelis–Menten–type kinetics with respect to isoniazid confirms the binding of oxidant and substrate to form a complex before the rate‐determining step. The existence of the inverse solvent kinetic isotope effect, k(H2O)/ k(D2O) = 0.7, in an acid‐catalyzed reaction proposes a multistep reaction mechanism. A decrease in the rate constant with an increase in [CTADC] reveals the formation of reverse micellar–type aggregates of CTADC in nonpolar solvents. In the presence of different ionic and nonionic surfactants, CTADC forms mixed aggregates and controls the reaction due to the charge on the interface and also due to partition of oxidant and substrate in two different domains. High negative entropy of activation (ΔS‡ = –145 and –159 J K−1 mol−1 in the absence and presence of acetic acid) proposes a more ordered and highly solvated transition state than the reactants. Furthermore, the solvent polarity‐reactivity relationship reveals (i) the presence of less polar and less ionic transition state compared to the reactants during the oxidation, (ii) differential contribution from nonpolar and dipolar aprotic solvents toward the reaction process, and (iii) the existence of polarity/hydrophobic switch at log P = 0.73. A suitable mechanism has been proposed on the basis of experimental results. These results may provide insight into the mechanism of isoniazid oxidation in hydrophobic environment and may assist in understanding the drug resistance in different location.

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Section: Resultsmentioning

confidence: 90%

Oxidation of Antitubercular Drug Isoniazid by a Lipopathic Oxidant, Cetyltrimethylammonium Dichromate: A Mechanistic Study

Garnayak

Patel

2015

Int. J. Chem. Kinet.

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“…The novel 2‐methyl‐2‐[3‐(5‐piperazin‐1‐yl‐[1,3,4]oxadiazol‐2‐yl)‐phenyl]‐propionitrile derivatives 8a – o , 9a – c , 10a – d , and 11a – d were synthesized according to Schemes and . We believe that this synthetic approach represents the most efficient route to a diverse array of 2,5‐disubstituted heterocyclics yet reported . The novel compounds were synthesized by the reactions of 2‐methyl‐2‐{3‐[5‐(piperazin‐1‐yl)‐1,3,4‐oxadiazol‐2‐yl]‐phenyl}‐propanenitrile ( 7 ) with different aromatic sulfonyl chlorides in the presence of triethylamine and dichloromethane as solvents with good yield ranging from 75% to 82%.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and In Vivo Anticonvulsant Activity of 2‐Methyl‐2‐[3‐(5‐piperazin‐1‐yl‐[1,3,4]oxadiazol‐2‐yl)‐phenyl]‐propionitrile Derivatives

Harish

Mohana

Mallesha³

et al. 2014

Archiv der Pharmazie

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A series of new 2-methyl-2-[3-(5-piperazin-1-yl-[1,3,4]oxadiazol-2-yl)-phenyl]-propionitrile derivatives 8a-o, 9a-c, 10a-d, and 11a-d were synthesized to meet the structural requirements essential for anticonvulsant property. The structures of all the synthesized compounds were confirmed by means of (1)H NMR, (13)C NMR, and mass spectral studies. The purity of the novel compounds was confirmed by elemental analyses. All the compounds were screened for their anticonvulsant activity against maximal electroshock (MES) seizure method and their neurotoxic effects were determined by rotorod test. Compounds 8d, 8e, and 8f were found to be the most potent of this series. The same compounds showed no neurotoxicity at the maximum dose administered (100 mg/kg). The efforts were also made to establish the structure-activity relationships among the synthesized compounds. The pharmacophore model was used to validate the anticonvulsant activity of the synthesized molecules.

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“…Further, prominent triplet signal at δ 1·32-1·36 ppm and a quartet signal at δ 4·26-4·32 ppm of ethoxy protons and a broad singlet of NH at δ 7·69 ppm in 1 H NMR confirmed the presence of ethyl carbamate group as the expected absorption pattern of carbamates. 26 Title compounds (4a-d) were synthesized in good yields by irradiating compounds 2 and 3 27,28 in dimethylformamide at 560W. The disappearance of nitrile (C≡N) stretch and appearance of absorption band at 1600·7 cm −1 related to the ν (C=N) stretch of triazole in IR and multiplet signals corresponding to aromatic protons at δ 7·38-7·43 ppm and 8·25-8·28 ppm and a broad singlet for NH proton of cyclic amide at δ 12·74 ppm in 1 H NMR confirmed the formation of title compounds (4a-d).…”

Section: Resultsmentioning

confidence: 99%

A facile microwave-assisted synthesis of 8,9-cycloalkathieno[3,2-e] [1,2,4]triazolo[1,5-c]pyrimidin-5(6H)-ones

et al. 2011

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Acyl hydrazines as precursors to acyl radicals

Cited by 67 publications

References 61 publications

Oxidation of Antitubercular Drug Isoniazid by a Lipopathic Oxidant, Cetyltrimethylammonium Dichromate: A Mechanistic Study

Oxidation of Antitubercular Drug Isoniazid by a Lipopathic Oxidant, Cetyltrimethylammonium Dichromate: A Mechanistic Study

Synthesis and In Vivo Anticonvulsant Activity of 2‐Methyl‐2‐[3‐(5‐piperazin‐1‐yl‐[1,3,4]oxadiazol‐2‐yl)‐phenyl]‐propionitrile Derivatives

A facile microwave-assisted synthesis of 8,9-cycloalkathieno[3,2-e] [1,2,4]triazolo[1,5-c]pyrimidin-5(6H)-ones

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