- Reaction of Pyridine-N-Oxides with Tertiary sp2-N-Nucleophiles: An Efficient Synthesis of Precursors for N-(Pyrid-2-yl)-Substituted N-Heterocyclic Carbenes
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N-(Pyrid-2-yl)-substituted azolium and pyridinium salts, precursors for hybrid NHC-containing ligands, were obtained with excellent regioselectivity, employing a deoxygenative CH-functionalization of pyridine-N-oxides with substituted imidazoles, thiazoles, and pyridine. Unlike the traditional SNAr-based methods, this approach provides high yields for substrates bearing substituents of different electronic nature. The utility of azolium and pyridinium salts thus prepared was also highlighted by the synthesis of pyridyl-substituted imidazolyl-2-thione, benzodiazepine as well as 2-aminopyridines.
- Bugaenko, Dmitry I.,Karchava, Alexander V.,Yurovskaya, Marina A.
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supporting information
p. 5777 - 5782
(2020/12/01)
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- Potent antimicrobial agents against azole-resistant fungi based on pyridinohydrazide and hydrazomethylpyridine structural motifs
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Abstract Schiff base derivatives have recently been shown to possess antimicrobial activity, and these derivatives include a limited number of salicylaldehyde hydrazones. To further explore this structure-activity relationship between salicylaldehyde hydrazones and antifungal activity, we previously synthesized and analyzed a large series of salicylaldehyde and formylpyridinetrione hydrazones for their ability to inhibit fungal growth of both azole-susceptible and azole-resistant species of Candida. While many of these analogs showed excellent growth inhibition with low mammalian cell toxicity, their activity did not extend to azole-resistant species of Candida. To further dissect the structural features necessary to inhibit azole-resistant fungal species, we synthesized a new class of modified salicylaldehyde derivatives and subsequently identified a series of modified pyridine-based hydrazones that had potent fungicidal antifungal activity against multiple Candida spp. Here we would like to present our synthetic procedures as well as the results from fungal growth inhibition assays, mammalian cell toxicity assays, time-kill assays and synergy studies of these novel pyridine-based hydrazones on both azole-susceptible and azole-resistant fungal species.
- Backes, Gregory L.,Jursic, Branko S.,Neumann, Donna M.
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p. 3397 - 3407
(2015/08/03)
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- SUBSTITUTED HETEROARYL ALDEHYDE COMPOUNDS AND METHODS FOR THEIR USE IN INCREASING TISSUE OXYGENATION
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Provided are substituted heteroaryl aldehydes and derivatives thereof that act as allosteric modulators of hemoglobin, methods and intermediates for their preparation, pharmaceutical compositions comprising the modulators, and methods for their use in treating disorders mediate by hemoglobin and disorders that would benefit from increased tissue oxygenation.
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Paragraph 0472; 0473
(2015/12/25)
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- SUBSTITUTED BENZALDEHYDE COMPOUNDS AND METHODS FOR THEIR USE IN INCREASING TISSUE OXYGENATION
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Provided are substituted benzaldehydes and derivatives thereof that act as allosteric modulators of hemoglobin, methods and intermediates for their preparation, pharmaceutical compositions comprising the modulators, and methods for their use in treating disorders mediate by hemoglobin and disorders that would benefit from increased tissue oxygenation.
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Paragraph 0140
(2013/07/19)
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- SUBSTITUTED HETEROARYL ALDEHYDE COMPOUNDS AND METHODS FOR THEIR USE IN INCREASING TISSUE OXYGENATION
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Provided are substituted heteroaryl aldehydes and derivatives thereof that act as allosteric modulators of hemoglobin, methods and intermediates for their preparation, pharmaceutical compositions comprising the modulators, and methods for their use in treating disorders mediate by hemoglobin and disorders that would benefit from increased tissue oxygenation.
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Paragraph 0247
(2013/07/19)
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- Heterocyclic Analogues of Phthalhydrazides: Cyclic Hydrazides of Pyridine 1-Oxide and Pyrazine 1,4-Dioxide Dicarboxylic Acids
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The synthesis of N-oxides of the cyclic hydrazides of pyridine and pyrazine o-dicarboxylic acids is described.Pyridopyridazine-5,8-dione 1-oxide, pyridopyridazine-1,4-dione 6-oxide, and pyrazinopyridazine-5,8-dione 1,2-dioxide, were obtained by direct oxidation of the parent hydrazides with peracetic acid.The pyridopyridazine derivatives were also unambiguously synthesized by treating the anhydrides or diesters of the relevant carboxylic acid 1-oxides with hydrazine hydrate.
- Paul, D. Brenton
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- Alkylation of Pyridine N-Oxides by Compounds with Active Methylene Protons
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Alkylation of nicotinic acid ethyl ester and 3-acetylpyridine N-oxides by compounds with active methylene protons is described. The tautomerism in products is observed and composition of tautomeric mixture for each product is determined.
- Mieczkowski, Jozef B.
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p. 255 - 259
(2007/10/02)
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- KINETICS OF THE N OXIDATION OF SOME COMPOUNDS OF THE PYRIDINE SERIES WITH PERBENZOIC ACID IN CHLOROFORM AND AQUEOUS DIOXANE
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A comparative study of the kinetics of the N oxidation of 19 derivatives of the pyridine series with perbenzoic acid in choroform and aqueous dioxane at 20, 25, 30, and 35 deg C was made.The rate constants, the parameters of the Arrhenius equation, and the activation energies of the N oxidation of the indicated monoazines were determined.The scale of the reactivities of the derivatives of the pyridine series was calculated within the framework of the Pearson hard-soft acid-base concept.
- Lohkov, R.E.
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p. 264 - 271
(2007/10/02)
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