Aromatic Hydrazine Research Articles

Simple Synthesis of Racemic Pyrrolo[2,3-b]indoles: Formal Total Synthesis of (±)-Physostigmine

Racemic pyrrolo[2,3-b]indoles were efficiently synthesized by the reaction of aromatic hydrazines with 4-chloro-2-methylbutanal. A formal total synthesis of physostigmine was achieved.

Synthesis and Reactions of Schiff Bases Containing an m-Phenoxyphenyl Group: I. N-Aryl-m-phenoxybenzylideneamines and N-Aryl-N'-(m-phenoxybenzylidene)hydrazines

Condensation of m-phenoxybenzaldehyde with aromatic amines and hydrazines gave the corresponding Schiff bases and m-phenoxybenzaldehyde arylhydrazones. The products are promising as biologically active substances, polyfunctional additives to rubber compounds, and inhibitors of acid corrosion.

Unprecedented Direct Conversion of N-N and N=N bonds to N-(tert-Butyloxy)-carbamates

For the first time a one step direct conversion of aromatic hydrazines and azo compounds to N-(tert-butoxycarbonyl) amines is achieved via reductive cleavage of N-N and N=N bonds using the inexpensive and safe hydride source polymethylhydrosiloxane (PMHS) and di-tert-butyl dicarbonate [(Boc) 2 O] in the presence of a catalytic amount of 10% Pd-C.

Characterization of chemical interferences in the determination of unsaturated aldehydes using aromatic hydrazine reagents and liquid chromatography.

A systematic investigation on interferences in the determination of unsaturated aldehydes and ketones using the 2,4-dinitrophenylhydrazine (DNPH) method is described. Acrolein, crotonaldehyde, methacrolein and 1-buten-3-one are derivatized with DNPH in the presence of an acidic catalyst to form the respective hydrazones. The unstable hydrazones react with excess reagent to form adducts. These are identified by high-performance liquid chromatography (HPLC)-mass spectrometry and spectroscopic techniques after cryogenic fraction collection of the adducts. The quantification of the unsaturated carbonyls with the DNPH method remains difficult. N-Methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH) was used as an alternative reagent for this purpose. As with DNPH, the formation of a side product is observed. In contrast to DNPH, the alteration of the pH immediately after sampling leads to only one reaction product, which is stable and storable in solution at 4 degrees C for 2 days.

Reduction of Hydrazines, Azo and Azoxy Compounds, and Amine N-Oxides with the NiCl 2·2H 2O–Li–DTBB (cat.) Combination

The NiCl 2·2H 2O/Li/DTBB (10 mol%) combination allows the reduction of aromatic hydrazines 1 (to amines), azo compounds 2 (to primary amines), azoxy compounds 3 (to azo compounds or to primary amines, depending on the reaction conditions) or amine N-oxides 4 (to tertiary amines), under mild reaction conditions (THF, room temperature).

The oxidation and reduction reactions of bovine serum amine oxidase. A kinetic study.

The presteady-state and steady-state kinetics of bovine serum amine oxidase (BSAO) were analyzed by stopped-flow transient spectroscopy. A simplified model of the catalytic cycle was found to describe the experimental data and the rate constants of the individual steps were used to calculate Michaelis parameters that agree with the direct determinations. In spite of many studies on selected reactions from the catalytic cycle, this is amongst the first efforts to provide a comprehensive kinetic description of the reactions of BSAO, whose results can be compared with the steady-state parameters. The reoxidation reaction by dioxygen is more complex than previously thought, in agreement with a recent report [Su, Q. & Klinman, J.P. (1998) Biochemistry 37, 12513-12525], and occurs in at least two steps whose rate constants, previously undetermined, have been measured. The reaction of the oxidized enzyme with the amine substrate is poorly determined in this type of experiment, thus irreversible combination with aromatic hydrazine inhibitors was used as a model system, demonstrating that the mechanism and rate constants of their reaction is fully compatible with an accurate description of the catalytic cycle with the physiological substrate. These results constitute a simplified, yet complete and consistent, description of the catalytic cycle and offer an interesting comparison with those obtained on plant amine oxidases; two steps of the catalytic cycle are significantly slower in BSAO than in pea seedling or lentil seedling amine oxidases, namely the reoxidation and the trans-iminative proton abstraction occurring in the enzyme-substrate complex. The former difference is rationalized as being due to the low to zero concentration of the semiquinolamine-radical intermediate, while the latter is less easily interpreted.

Ultrafast intermolecular electron transfer in coumarin–hydrazine system

Ultrafast intermolecular electron transfer (ET) from electron-donating solvents to excited coumarin dyes has been investigated by the femtosecond fluorescence up-conversion technique. In this work we have used hydrazine derivatives as an electron-donating solvent to investigate the effects of very low oxidation potentials of electron-donating solvents on the ET dynamics. The ET rate with the aromatic hydrazines is much faster (sub-picoseconds) than that with the aliphatic hydrazine (a few tens of picoseconds), although the oxidation potential of the aliphatic hydrazine is lower than that of the aromatic hydrazine. However, the coumarin–hydrazine systems used in this study are not in the so-called Marcus inverted region. The results are discussed in light of the theoretical prediction from the two-dimensional ET model. We find that the electronic matrix element should be largely different between the aromatic and aliphatic hydrazine cases, which may result from the different molecular orbitals of these molecules.

New Synthesis of Pyrido[2,3-d] and [3,2-d]Oxazines

N-Hydroxyquinolinimide 1 reacts with each of aromatic amines, hydrazine hydrate and aromatic hydrocarbons to give arylcarbamoyl pyridines 2, pyrrolopyridines 3, pyridopyridazines 4 and pyridooxazinones 5 and 6. The heterocycles 5 and 6 can be transformed to the condensed systems, triazolopyridopyridazines 14 and 15 through series of reactions.

SYNTHESIS OF SOME SACCHARIN DERIVATIVES OF EXPECTED BIOLOGICAL ACTIVITY BASED ON N-(SACCHARINYL)-ACETIC ACID AZIDE

Abstract Azide was prepared from the corresponding acid chloride . The base catalyzed decomposition with aromatic amines, aminobenzoic acids and/or hydrazines afforded the corresponding anilides and/or hydrazides via azido group displacement. Compounds and were refluxed in Ac2O to give 1,3,4-oxadiazole derivatives and . Lewis acid catalyzed decomposition of azide with anhyd. AlCl3 in dry aromatic substrates gave the corresponding ketones . Also, the reaction of azide with glycine gave .

Regiocontrolled Syntheses of 3- or 5-Fluorinated Pyrazoles from 2,2-Difluorovinyl Ketones(1).

2,2-Difluorovinyl ketones 1 react with monosubstituted hydrazines to afford 5-fluoropyrazoles in a regioselective manner via replacement of the fluorine by the substituted nitrogen of the hydrazines and dehydration between the carbonyl group of 1 and the NH(2) end. The reactions are successfully effected for both aliphatic and aromatic hydrazines in aqueous ethanol under neutral conditions and in THF under basic conditions with butyllithium, respectively. A similar ring-forming reaction of 1 with hydrazine monohydrate is induced by the addition of trifluoroacetic acid to give N-unsubstituted 3-fluoropyrazoles, which in turn react with alkyl and aryl halides in the presence of sodium hydride, leading to a regiocontrolled synthesis of 3-fluoropyrazoles.

The Knoevenagel reaction of malononitrile with acetylacetone: New route of pyrazole, pyrazolo[2,3-C]pyridine, benzene, pyridazine and benzo[C]pyridazine derivatives

The Knoevenagal reaction of malononitrile and acetylacetonegave the acyclic product 3 whichwas separated in a good yield and identified. The reactivity of 3 towards some chemical reagents is studied. Thus, the reaction of 3 with aromatic aldehydes, hydrazines and cyanomethylene derivativesgave products 6–12. Reaction of 3 with benzenediazonium chloridegave the primidine derivative 14.

ChemInform Abstract: Molecular Yardsticks: Synthesis of Higher Homologs of 7,12‐Dihydropyrido(3,4‐b:5,4‐b′)diindole. Probing the Dimensions of the Benzodiazepine Receptor Inverse Agonist Site.

AbstractReaction of the benzoyltetrahydrooxo‐β‐carboline (I) with the aromatic hydrazines (II) or (IV) leads to the formation of the fused pyrroles (III) or (V).

ChemInform Abstract: Inhibitors of Cholesterol Biosynthesis. Part 2. 1,3,5‐Trisubstituted (2‐(Tetrahydro‐4‐hydroxy‐2‐oxopyran‐6‐yl)ethyl)pyrazoles.

AbstractCyclocondensation of the substituted 1,3‐diketone (III) with aromatic hydrazines such as (IV) yields a mixture of the regioisomeric pyrazoles (V) and (VI).

ChemInform Abstract: Synthesis of Some 1‐Substituted 3‐Methyl‐5‐(2′,4′,6′‐trimethoxyphenyl)‐ 4‐(N1‐substituted‐p‐sulfamylbenzeneazo)pyrazoles as Potential Antifungal and Antibacterial Agents.

AbstractCoupling of the diazotized sulfonamide bases (II) with the diketone (I) and subsequent cyclization with the aromatic hydrazines (IV) produce the pyrazoles (V).

ChemInform Abstract: REACTION OF 2‐DIMETHYLAMINOMETHYLENE‐1,3‐DIONES WITH DINUCLEOPHILES. IV. SYNTHESIS OF 5,7‐DIHYDROTHIOPYRANO(3,4‐C)PYRAZOL‐4(1H)‐ONES, 5H‐THIOPYRANO(4,3‐D)ISOXAZOL‐4(7H)‐ONE AND 6H‐THIOPYRANO(3,4‐D)PYRIMIDIN‐5(8H)‐ONES

AbstractDas Thiopyran‐3,5‐dion (I) reagiert mit Dimethylformaldehydacetal (II) zum Dimethyl‐ 150 aminomethylen‐Derivat (III), das mit Hydrazinen (IV), Hydroxylamin (VII) oder mit den Amidinen (VIII) z‐u den Bicyclen (V), (VI) oder (IX) in hohen Ausbeuten führt.

Reaction of 2‐dimethylaminomethylene‐1,3‐diones with Dinucleophiles. IV. Synthesis of 5,7‐dihydrothiopyrano[3,4‐c]pyrazol‐4(1H)‐ones, 5H‐Thiopyrano[4,3‐d]isoxazol‐4(7H)‐one and 6H‐Thiopyrano[3,4‐d]pyrimidin‐5(8H)‐ones

AbstractThe reaction of 2H‐thiopyran‐3,5(4H,6H)‐dione with N,N‐dimethylformamide dimethyl acetal gave in good yield 4‐dimethylaminomethylene‐2H‐thiopyran‐3,5(4H,6H)dione (II), which afforded 1‐substituted 5,7‐dihydrothiopyrano[3,4‐c]pyrazol‐4(1H)‐ones with aliphatic and aromatic hydrazines, 5H‐thiopyrano[4,3‐d]isoxazol‐4(7H)‐one (IV) with hydroxylamine hydrochloride and 2‐substituted 6H‐thiopyrano[3,4‐d]pyrimidin‐5(8H)‐ones with amidines and guanidines, generally in satisfactory yields. 4‐(t‐Butylhydrazonoformyl)‐2H‐thiopyran‐3,5(4H,6H)‐dione was isolated as an intermediate in the reaction of II with t‐butylhydrazine, whereas formamidine gave with II 4‐iminoformyl‐2H‐thiopyran‐3,5(4H,6H)‐dione as the sole product. The isoxazole IV isomerized easily with sodium methoxide to 3,4,5,6‐tetrahydro‐5,5‐dihydroxy‐3‐oxo‐2H‐thiopyrano‐4‐carbonitrile.

Structural characteristics of compounds that can be activated to chemically reactive metabolites: use for a prediction of a carcinogenic potential.

Many mutagens and carcinogens act via covalent interaction of metabolic intermediates with DNA in the target cell. This report groups those structural elements which are often found to form the basis for a metabolism to such chemically reactive metabolites. Compounds which are chemically reactive per se and which do not require metabolic activation form group 1. Group 2 comprises of olefins and aromatic hydrocarbons where the oxidation via an epoxide can be responsible for the generation of reactive species. Aromatic amines, hydrazines, and nitrosamines form group 3 requiring an oxidation of a nitrogen atom or of a carbon atom in alpha position to a nitrosated amine. Group 4 compounds are halogenated hydrocarbons which can either give rise to radicals or can form an olefin (group 2) upon dehydrohalogenation. Group 5 compounds depend upon some preceding enzymatic activity either not available in the target cell or acting on positions in the molecule which are not directly involved in the subsequent formation of electrophilic atoms. Examples for each group are taken from the "List of Chemicals and Industrial Processes Associated with Cancer in Humans" as compiled by the International Agency for the Research on Cancer, and it is shown that 91% of the organic carcinogens would have been detected on the basis of structural elements characteristic for group 1-5. As opposed to this very high sensitivity, the specificity (the true negative fraction) of using this approach as a short-term test for carcinogenicity is shown to be bad because detoxification pathways have so far not been taken into account. These competing processes are so complex, however, that either only very extensive knowledge about pharmacokinetics, stability, and reactivity will be required or that in vivo systems have to be used to predict, on a quantitative basis, the damage expected on the DNA. DNA-binding experiments in vivo are presented with benzene and toluene to demonstrate one possible way for an experimental assessment and it is shown that the detoxification reaction at the methyl group available only in toluene gives rise to a reduction by at least a factor of forty for the binding to rat liver DNA. This quantitative approach available with DNA-binding tests in vivo, also allows evaluation as to whether reactive metabolites and their DNA binding are always the most important single activities contributing to the overall carcinogenicity of a chemical.(ABSTRACT TRUNCATED AT 400 WORDS)

Nitrous acid deamination of 1,1-disubstituted aromatic hydrazines

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNitrous acid deamination of 1,1-disubstituted aromatic hydrazinesMichael De Rosa and Paul HaberfieldCite this: J. Org. Chem. 1981, 46, 13, 2639–2643Publication Date (Print):June 1, 1981Publication History Published online1 May 2002Published inissue 1 June 1981https://doi.org/10.1021/jo00326a006RIGHTS & PERMISSIONSArticle Views436Altmetric-Citations19LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (740 KB) Get e-Alerts Get e-Alerts

Reaction of 2,3-dioxo-4-(N,N-dimethylaminomethylene)hexahydroazepine with hydroxylamine

Depending on the conditions selected, the reaction of 2,3-dioxo-4-(N,N-dimethylaminomethylene)hexahydroazepine with hydroxylamine gives 2,3-dioxo-4-formylhexahydroazepine 4-oxime, 8-oxo-8H-4,5,6,7-tetrahydroisoxazolo[5,4-c]azepine, or 2-oxo-3-hydroxy-4-cyano-2H-1,5,6,7-tetrahydroazepine. The reaction of the latter with aromatic amines and hydrazine hydrate was used to synthesize 3-arylamino-2-oxo-4-cyano-2H-1,5,6,7-tetrahydroazepines and 3-amino-8-oxo-8H-4,5,6,7-tetra-hydropyrazolo[5,4-c]azepine, respectively. The structures of the compounds obtained were confirmed by the IR, UV, and PMR spectra.

Inhibition of kynurenine hydrolase by benserazide, carbidopa and other aromatic hydrazine derivatives: evidence for sub-clinical iatrogenic niacin deficiency [proceedings

Inhibition of kynurenine hydrolase by benserazide, carbidopa and other aromatic hydrazine derivatives: evidence for sub-clinical iatrogenic niacin deficiency [proceedings