Selenium‐Containing Heterocycles from Isoselenocyanates: Use of Hydrazine for the Synthesis of 1,3,4‐Selenadiazine Derivatives

Aryl isoselenocyanates 1 react with different phenacyl halides 2 in the presence of hydrazine hydrate in a one‐pot reaction to give selenadiazines 3a – 3f in good‐to‐excellent yields.     

One-pot synthesis of trisubstituted pyrazoles <Emphasis Type="Italic">via</Emphasis> multicomponent approach

An efficient one-pot multicomponent reaction for the synthesis of 1-aryl- or 1-heteryl-substituted 3,5-dimethylpyrazoles with excellent yields has been described. Reaction of 3-(2-bromoacetyl)coumarins or phenacyl bromides with acetylacetone and hydrazine hydrate in ethanol afforded the corresponding 3,5-dimethylpyrazoles in good yields. All the synthesized compounds were characterized by their analytical and spectral data.     

SYNTHESIS AND REACTIONS OF SOME NEW THIENO[2,3-b]-PYRIDINES AND THE ANTIMICROBIAL EFFECTS

Abstract

3,5-Dicyano-6-mercapto-4-phenylpyridin-2(1H)-one (1) was reacted with ethyl chloroacetate to give compound (II) which on reaction with hydrazine hydrate gave the corresponding hydrazide derivative (III). Acylation of (III) with acetic acid, phenylisocyanate, or phenylisothiocyanate gave different monoacyl derivatives (IV-VI). Condensation of III with aromatic aldehydes and acetylacetone gave compounds VII_a-c, VIII respectively. Compound I was reacted with chloroanilides, bromoacetone and phenacyl bromide to yield the IX-XI; these and compound II gave thieno[2,3-b]-pyridines (XU-XV) on treatment with sodium ethoxide solution. Reaction of XII with acetic anhydride gave the diacetyl derivative XVI. Hydrolysis of compound XII with sodium hydroxide gave the corresponding acid (XVII) which on treatment with acetic anhydride gave the oxazine derivative (XVIII). Reaction of oxazine compound XVIII with ammonium acetate and hydrazine hydrate gave pyrido[3′,2′:4,5] thieno[3,2-d]pyrimidin-4.7-dione derivative (XIX) and (XX) respectively. The N-amino derivative (XX) was reacted with 4-nitrobenzaldehyde to give the corresponding azomethine (XXI).

Significant in vitro gram-positive and gram negative antibacterial activities as well as anti-fungal effect were observed for some members of the series.     

Synthesis and antimicrobial evaluation of some 1,3-thiazole, 1,3,4-thiadiazole, 1,2,4-triazole, and 1,2,4-triazolo[3,4-b][1,3,4]-thiadiazine derivatives including a 5-(benzofuran-2-yl)-1-phenylpyrazole moiety

Abstract  

Potassium hydrazinecarbodithioate were prepared by treatment of acid hydrazides with carbon disulfide in the presence of potassium hydroxide. Reaction of this potassium salt with hydrazine hydrate, phenacyl bromide, or hydrazonoyl chlorides afforded 1,2,4-triazole, 1,3-thiazole, and 1,3,4-thiadiazoles. Reaction of 1,2,4-triazole with phenacyl bromide or hydrazonoyl chlorides afforded the corresponding 1,2,4-triazolo[3,4-b][1, 3, 4]-thiadiazines. All these new compounds were screened for antibacterial and antifungal activity. Some had promising activity.     

Reaction of 3-Arylaminobenzofuro-, 3-Arylaminobenzothieno-, and 3-Arylaminoindolo[2,3-<Emphasis Type="Italic">c</Emphasis>]pyrylium Salts with Nucleophilic Reagents

We have studied the reactions of 3-arylaminobenzofuro-, 3-arylaminobenzothieno-, and 3-arylaminoindolo[2,3-c]pyrylium salts with ammonium acetate, primary amines, and hydrazine hydrate. In an alcoholic medium, primary amines and hydrazine hydrate open up the pyrylium ring to form arylamides of 2-(N-benzylmethylketimine)hetaryl-3-acetic acids or the corresponding hydrazones, where further heterocyclization does not occur. Upon treatment with ammonium acetate in acetic acid, 2-aryl-1-methylhetero[2,3-c]pyridin-3-(2H)-ones are formed along with their 2-unsubstituted analogs.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 601–612, April, 2005.     

Conventional and microwave reactions of 1,3-diaryl-5,4-enaminonitrile-pyrazole derivative with expected antimicrobial and anticancer activities

The present study illustrates conventional and microwave reactions of 5-amino-1,3-diaryl-pyrazole-4-carbonitrile derivative with phenacyl bromide under different conditions, hydrazine hydrate, hydroxylamine hydrochloride, tetrahydrofuran, phthalic anhydride, and cyanoacetic acid. The product of the latter reaction condensed with hydrazine and cyclohexanone to give the pyrazolotriazepine acetonitrile and cyclohexylidene derivatives. The new cyclohexylidene is used as key intermediate to synthesize some new spiro compounds. The behavior of the starting compound with benzaldehyde, ethylenediamine, phenylenediamine, sodium azide, 1-amino-2-hydroxynaphthalene-7-sulphonic acid, diethylmalonate, terephthalaldehyde, acetyl chloride, and acetic anhydride were also investigated. The new compounds structures were established from spectroscopic data. Some of the new pyrazole derivatives showed antibacterial and anticancer activities.     

Synthesis and antimicrobial evaluation of some 1,3-thiazole, 1,3,4-thiadiazole, 1,2,4-triazole,and 1,2,4-triazolo[3,4-<Emphasis Type="Italic">b</Emphasis>][1,3,4]-thiadiazine derivatives including a 5-(benzofuran-2-yl)-1-phenylpyrazole moiety

Abstract  Potassium hydrazinecarbodithioate were prepared by treatment of acid hydrazides with carbon disulfide in the presence of potassium hydroxide. Reaction of this potassium salt with hydrazine hydrate, phenacyl bromide, or hydrazonoyl chlorides afforded 1,2,4-triazole, 1,3-thiazole, and 1,3,4-thiadiazoles. Reaction of 1,2,4-triazole with phenacyl bromide or hydrazonoyl chlorides afforded the corresponding 1,2,4-triazolo[3,4-b][1, 3, 4]-thiadiazines. All these new compounds were screened for antibacterial and antifungal activity. Some had promising activity. Graphical abstract        

SOME REACTIONS OF 3-AMINO-2-CARBOETHOXY-4,6-DIMETHYLTHIENO[2,3-b]-PYRIDINE. SYNTHESIS OF SOME NEW THIENOPYRIDOPYRIMIDINES

Abstract

Thienopyridine oxazinone (1) has been prepared and explored as a precursor by its reaction with some reagents namely, ammonium acetate, aliphatic amines, aromatic amines, hydrazine hydrate, thiosemicarbazide, and ethyl glycinate to give pyridothienopyrimidines (11-VII). The pyrimidinone compound (11) was converted to the 4-chloro derivative (X) by its reaction with excess POCl₃ Interaction of the 4-chlorocompound (X) with some reagents namely, hydrazine hydrate, methyl amine, aniline, sodium thiophenolate, ethyl glycinate, thiosemicarbazide and thiourea, yielded pyridothieno-pyrimidine derivatives (XI-XVII) substituted at 4-position, respectively.     

Phase Transfer Catalyzed Synthesis of 1,6-Diaroyldithiohydrazodicarbonamide Derivatives

Reaction of hydrazine hydrate with aroyl chloride and ammonium thiocyanate under the condition of solid-liquid phase transfer catalysis using polyethylene glycol-600 (PEG-600) as the catalyst yielded 1, 6-diaroyldithiohydrazodicarbonamides 3a—3h in good to excellent yield.     

A Novel Synthesis of Some 1,4‐Phenylene‐bis‐heterocyclic Derivatives and of Some Pyran,Pyrano[2,3‐c]pyrazole,and Pyrano[2,3‐d]pyrimidine Derivatives [1]

p‐Diacetyl benzene 1 undergoes bromination to afford p‐bromoacetyl phenacyl bromide 2 . Compound 2 reacts with twofold excess of malononitrile to afford 2‐{2‐[4‐(3,3‐Dicyanopropionyl)‐phenyl]‐2‐oxo‐ethyl}‐malononitrile 3 . Compound 3 could be cyclized to afford the 1,4‐phenylene‐bis‐furan derivative 4 . Compound 3 reacts also with a twofold excess of hydrazine hydrate and phenyl hydrazine under dry conditions at RT to afford the bis‐pyrazole derivatives 5a , 5b , respectively. The reaction of 5a , 5b with the same reagents in refluxing dioxane afforded the bis‐pyrazolopyridazine derivatives 7a , 7b , respectively. The azo coupling of compound 3 with arene diazonium salts afforded the bis‐pyrazole derivatives 9a , 9b , 9c . The β‐keto esters 10a , 10b react with benzaldehyde and malononitrile in a one pot synthesis to afford the pyran derivatives 11a , 11b . These latter compounds react with hydrazine hydrate and urea derivatives to afford the pyrano[2,3‐c]pyrazoles 15a , 15b and the pyrano[2,3‐d]pyrimidine derivatives 17a , 17b , respectively.     

The synthesis of heterocyclic derivatives from pyran-2-ones and hydrazine hydrate. Ammonium cerium(IV) nitrate as an efficient oxidant in pyridazine chemistry

A novel reaction of 3-amino-2H-pyran-2-ones and their fused derivatives with hydrazine hydrate leading to the corresponding pyridazine derivatives is reported. Further oxidation with ammonium cerium(IV) nitrate (CAN, from Cerium(IV) Ammonium Nitrate) yields a collection of pyridazine-3-carboxylates.     

Synthesis, reactions and biological activity of 2-substituted 3-cyano-4,6-dimethylpyridine derivatives

The reaction of 2-chloro-4,6-dimethylpyridine-3-carbonitrile with hydrazine hydrate, hydroxylamine, and anthranilic acid afforded the corresponding pyrazolo, isoxazolo, and pyridoquinazoline derivatives. Alkylation of 2-mercapto-4,6-dimethylpyridine-3-carbonitrile with ethyl chloroacetate or phenacyl bromide followed by cyclization in NaOH gave thienopyridine derivatives. Diazotization of ethyl 3-amino-4,6-dimethylthiеno[2,3-b]pyridine-2-carboxylate followed by the reaction with thiourea, guanidine carbonate, and hydroxylamine hydrochloride gave the corresponding thienopyridine derivatives. The biological activity of some new compounds has been discussed. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 43–51, Januar, 2009.     

Ion-exchange resin catalysts in the liquid-phase hydrazinolysis of cinnamic acid

The catalytic activity of a synthetic ion-exchange resins has been studied in the reaction of cinnamic acid with hydrazine (aqueous medium, 363 K, 1.0–2.5 h) yielding the corresponding hydrazide. Efficient catalysts for the process are the anion-exchange resins AV-17-8 and AN-31. The modifying effect of the substrate—hydrazine hydrate—on the catalytic properties of the ion-exchange systems has been demonstrated. On the basis of IR spectroscopic studies, a plausible process mechanism was suggested. It involves polymer-bound quaternary ammonium ions of the anion exchanger.     

Studies on enaminonitriles: A new synthesis of 1,3‐substituted pyrazole‐4‐carbonitrile

3‐Diethylaminoacrylonitrile ( 1 ) reacts with hydrazonyl halides ( 2a‐d ) to yield 1,3‐disubstituted pyrazole‐4‐carbonitriles 5a‐d. The acetyl 1‐p‐chlorophenylpyrazole‐4‐carbonitrile ( 5a ) condensed with hydrazine hydrate to yield the bishydrazone 10 and with dimethylformamide dimethylacetal to yield 1‐aryl‐3‐(3‐dimethylamino)acryloyl pyrazole‐4‐carbonitrile ( 11 ). This enamine reacts with hydrazine hydrate to yield the pyrazolylpyrazole ( 12 ) and with naphthoquinone to yield the 3‐naphthofuranoyl pyrazole 13. The pyra‐zolyl pyridine derivative 14 was obtained upon treatment of 11 with acetylacetone in the presence of ammonium acetate. Compound 11 was coupled with p‐chlorobenzene diazonium chloride to yield the hydrazone 16 that was coupled further with p‐chlorobenzenediazonium chloride to yield the formazane 18.     

Preparation, characterisation and thermal properties of hydrazinium derivatives. Part III

Hydrazinium acetate, metavanadate, sulfite, sulphamate and thiocyanate have been prepared by the reaction of corresponding ammonium salts with hydrazine hydrate. The compounds were characterised by chemical analysis and infrared spectra. Thermal behaviour of these hydrazinium derivatives have been investigated using thermogravimetry and differential thermal analysis.     

Activated Nitriles with Ammonium Benzyldithiocarbamate,Synthesis of Thietane Derivatives

4-Aryl-2-iminothietane-3-carbonitriles 3 were obtained in a moderate yield via the reaction of substituted arylidene malononitriles with ammonium benzyldithio-carbamate. The reaction of 3a with hydrazine hydrate, ethyl carbazate, phenylisothiocyanate, and carbon disulphide have been investigated.     

Preparation and Properties of a Representative of a New Series of Chalcogen-containing 1,5-Diketones, Di(1-oxo-1,2,3,4-tetrahydro-2-naphthyl) Sulfide

Di(1-oxo-1,2,3,4-tetrahydro-2-naphthyl) sulfide has been obtained and its behavior towards hydrogen sulfide in situ, ammonium acetate, hydrazine hydrate, and hydrogen peroxide has been studied. The structure of the compounds synthesized was established by IR and by ¹H and ¹³C NMR spectroscopy and by chromato-mass spectrometry.     

Pyridazine Derivatives and Related Compounds,Part 1. Some Reactions with 4-Cyano-5,6-Diphenyl-2,3-Dihydropyridazine-3-One

4-Cyano-5,6-diphenyl-2,3-dihydropyridazine-3-onc 1 reacts with phosphorous oxychloride to give 70% of the corresponding 3-chloro derivative 2. Treating 2 with anthranilic acid in butanol, 4-cyano-2,3-diphenyl-10H-pyridazino[6,1-b]quinoxaline-10-one, 3 was obtained. Compound 1 reacts with phosphorous pentasulphide to give 3-mercapto derivative 4, which was converted by acrylonitrile to S-(2-cyanoethyl)pyridazine derivative 5. Compound 4 reacts with ethyl bromoacetate and with phenacyl bromide gave the corresponding thieno[2,3-c] pyridazine derivatives 8, 9, Alkylation of 1 with ethyl chloroacetate afforded 3-0-carbethoxymethyl derivative 10. Compound 10 reacts with amines (aniline, hydrazine) to give the corresponding amide and acid hydrazide 13, 12 respectively. Hydrolysis of 10 with sodium hydroxide gave the corresponding acid derivative 11. Treating 1 with methyl iodide, 3-0-methyl derivative 14 was obtained, which was converted by ammonium acetate/acetic acid to 3-amino-4-cyano-5,6-diphenyl pyridazine 15. Compound 1 reacts with methyl magnesium iodide gave 4-acetyl derivative 16, which was reacted with hydrazine, phenyl hydrazine and with hydroxylamine to give the substituted I H pyrazolo [3,4-c] pyridazine 17 a,b and isoxazolo [5,4-c] pyridazine 18 derivatives respectively.     

EVALUATION OF THE N-PHTHALOYL MOIETY AS PROTECTING GROUP IN AMINOACYLPHOSPHONIC DERIVATIVES

Abstract

Reaction of dimethyl benzoylphosphonate with hydrazine hydrate gave exclusively benzhydrazide. Reaction of methyl lithium benzoylphosphonate with hydrazine hydrate gave the corresponding hydrazone (3) as a 65:35 mixture of E and Z isomers. Reaction of hydrazine hydrate with diisopropyl 4phthalimidobutanoylphosphonate gave mainly products resulting from nucleophilic attack of hydrazine on the carbonyl of the acylphosphonate and only a small percentage of phthalhydrazide. From our results it appears that the N-phthaloyl protecting group is not suitable for the transient protection of amino groups during attempts to synthesize aminoacylphosphonates.     

Highly efficient reduction of nitro compounds: Recyclable Pd/C-catalyzed transfer hydrogenation with ammonium formate or hydrazine hydrate as hydrogen source

Herein, we described a highly efficient heterogeneous Pd/C-catalyzed transfer hydrogenation of nitro compounds for the synthesis of primary amines, using ammonium formate and hydrazine hydrate as hydrogen source independently. The products were obtained with up to >99% yield. Furthermore, gram scale and recycling of catalyst had been tested with well results.