Enamines in Heterocyclic Synthesis: A Novel Simple and Efficient Route to Condensed Pyridazines

An efficient and easy preparation of enamine derivatives, via active methyl and methylene compounds by in situ-generated 1-(diethoxymethyl)piperidine, produced from the mixture of triethyl orthoformate/piperidine/DMF, are described. Some new pyridazinone derivatives have been synthesized from the reaction of enamines with hydrazine hydrate and cyanoacid hydrazide.

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In-situ visualization of N2 evolution in operating direct hydrazine hydrate fuel cell by soft X-ray radiography

Journal of Power Sources ◽

10.1016/j.jpowsour.2013.11.108 ◽

2014 ◽

Vol 252 ◽

pp. 35-42 ◽

Cited By ~ 12

Author(s):

Tomokazu Sakamoto ◽

Phengxay Deevanhxay ◽

Koichiro Asazawa ◽

Shohji Tsushima ◽

Shuichiro Hirai ◽

...

Keyword(s):

Fuel Cell ◽

Hydrazine Hydrate ◽

X Ray ◽

In Situ Visualization

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Enaminones as Building Blocks In Heterocyclic Synthesis: A New One Pot Synthesis of Polyfunctional Substituted Pyridines

Zeitschrift für Naturforschung B ◽

10.1515/znb-2001-1016 ◽

2001 ◽

Vol 56 (10) ◽

pp. 1074-1078 ◽

Cited By ~ 13

Author(s):

Samia Michel Agamy ◽

Mervat Mohammed Abdel-Khalik ◽

Mona Hassan Mohamed ◽

Mohammed Hilmy Elnagdi

Keyword(s):

Acetic Acid ◽

Double Bond ◽

Aromatic Aldehyde ◽

Michael Addition ◽

Ammonium Acetate ◽

Building Blocks ◽

Heterocyclic Synthesis ◽

One Pot ◽

Active Methyl ◽

Substituted Pyridines

Enaminones react with a variety of active methyl and methylene reagents in presence of ammonium acetate to yield functionally substituted pyridines in good yields. The reaction proceeded via initial Michael addition across the double bond followed by cyclization. The reaction of enaminone with aromatic aldehyde in acetic acid/ammonium acetate afforded the dihydropyridine that was oxidized to the corresponding pyridine.

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In situ derived Fe/N/S-codoped carbon nanotubes from ZIF-8 crystals as efficient electrocatalysts for the oxygen reduction reaction and zinc–air batteries

Journal of Materials Chemistry A ◽

10.1039/c8ta07849a ◽

2018 ◽

Vol 6 (41) ◽

pp. 20093-20099 ◽

Cited By ~ 64

Author(s):

Huihui Jin ◽

Huang Zhou ◽

Wenqiang Li ◽

Zhihao Wang ◽

Jinlong Yang ◽

...

Keyword(s):

Carbon Nanotubes ◽

Oxygen Reduction Reaction ◽

Hydrazine Hydrate ◽

Oxygen Reduction ◽

High Performance ◽

Reduction Reaction ◽

Zinc Air Batteries

Hydrazine hydrate was employed to prevent Fe agglomeration and sulphate ions were used as the S source, which together led to Fe/N/S-CNTs with high performance.

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Enamines in Heterocyclic Synthesis: A Novel Simple and Efficient Route to Condensed Pyridazines

Zeitschrift für Naturforschung B ◽

10.5560/znb.2011.66b0597 ◽

2011 ◽

Vol 66 ◽

pp. 0597 ◽

Cited By ~ 1

Author(s):

E. S. Darwish ◽

M. A. Abdelrahman ◽

A. M. Salaheldin

Keyword(s):

Heterocyclic Synthesis ◽

Efficient Route

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A facile synthetic route to benzimidazolium salts bearing bulky aromatic N-substituents

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.11.182 ◽

2015 ◽

Vol 11 ◽

pp. 1656-1666 ◽

Cited By ~ 8

Author(s):

Gabriele Grieco ◽

Olivier Blacque ◽

Heinz Berke

Keyword(s):

Imidazole Ring ◽

Triethyl Orthoformate ◽

Ring Closure ◽

Synthetic Route ◽

Benzimidazolium Salts ◽

Work Up

An atom-economic synthetic route to benzimidazolium salts is presented. The annulated polycyclic systems: 1,3-bis(2,4,6-trimethylphenyl)-1H-benzo[d]imidazol-3-ium chloride (1-Cl), 1,3-bis(2,6-diisopropylphenyl)-1H-benzo[d]imidazol-3-ium chloride (2-Cl), 1,3-diphenyl-1H-benzo[d]imidazol-3-ium chloride (3-Cl), and 1,3-di(pyridin-2-yl)-1H-benzo[d]imidazol-3-ium chloride (4-Cl) were prepared in a two-step synthesis avoiding chromatographic work-up. In the key step triethyl orthoformate is reacted with the correspondingN1,N2-diarylbenzene-1,2-diamines and then further transformed in situ, by alkoxy abstraction using trimethylsilyl chloride (TMSCl), and concomitant imidazole ring closure.

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Electrodeposition of PtNPs on the LBL assembled multilayer films of (PDDA-GS/PEDOT:PSS)n and their electrocatalytic activity toward methanol oxidation

RSC Advances ◽

10.1039/c6ra28784k ◽

2017 ◽

Vol 7 (27) ◽

pp. 16371-16378 ◽

Cited By ~ 7

Author(s):

Hui Li ◽

Li-Ping Jia ◽

Rong-Na Ma ◽

Wen-Li Jia ◽

Huai-Sheng Wang

Keyword(s):

Hydrazine Hydrate ◽

Methanol Oxidation ◽

Electrocatalytic Activity ◽

Multilayer Films ◽

Graphene Sheets ◽

Functionalized Graphene ◽

Diallyldimethylammonium Chloride

In the present work, PDDA-functionalized graphene sheets (PDDA-GS) were prepared by reduction with hydrazine hydrate in situ in the presence of poly(diallyldimethylammonium chloride) (PDDA).

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γ-Oxo Carboxylic Acids in Heterocyclic Synthesis, III. Synthesis of Biologically Active 4-Benzylamino-6-(5,5-dioxodibenzothiophen- 2-yl)-2,3,4,5-tetrahydropyridazin-3-ones

Zeitschrift für Naturforschung B ◽

10.1515/znb-2002-0613 ◽

2002 ◽

Vol 57 (6) ◽

pp. 668-676 ◽

Cited By ~ 5

Author(s):

Ashraf A. F. Wasfy ◽

Mohamed M. H. Arief ◽

Mahassen S. Amine ◽

Shafey G. Donia ◽

Aly A. Aly

Keyword(s):

Hydrazine Hydrate ◽

Sodium Azide ◽

Aromatic Aldehydes ◽

Biologically Active ◽

Secondary Amines ◽

Keto Acid ◽

Heterocyclic Synthesis ◽

Reaction Conditions ◽

Carbon Nucleophiles ◽

Pyrazolone Derivative

α-Benzylamino-β-(5,5-dioxodibenzothiophen-2-carbonyl)propionic acid (1) has been synthesized by treating the corresponding β-aroylacrylic acid with benzylamine in dry benzene. On treatment with hydrazine hydrate the keto acid 1 furnishes the corresponding pyridazinone derivative 2. The behaviour of 2 towards carbon electrophiles, namely, ethyl chloroacetate, acrylonitrile, formaldehyde and secondary amines (under Mannich reaction conditions), aromatic aldehydes and carbon nucleophiles, namely, POCl3/PCl3 and P2S5 has been investigated. The 3-chloropyridazine derivative 13 reacts with hydrazine hydrate to give the 3-hydrazino derivative 14. On treatment with ethyl acetoacetate and/or acetylacetone the hydrazine 14 undergoes cyclization to afford pyrazolone derivative 16 and 3-(3,5-dimethylpyrazol- 1-yl)pyridazine derivative 17, respectively. On reaction with acetylhydrazine in boiling butanol and/or sodium azide in DMF the 3-chloropyridazine derivative 13 affords the triazolo[4,3-b]pyridazine 18 and the tetrazolo[1,5-b]pyridazine 19, respectively. The anti-microbial activity of the synthesized derivatives has been investigated.

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Fluorine-Containing Heterocycles: Part I. Synthesis of New 7-(2-thienyl)-9-Trifluoromethylpyrido[3′,2′:4,5]Thieno[3,2-d]Pyrimidines and Related Fused Tetracyclic Systems

Journal of Chemical Research ◽

10.3184/0308234054213726 ◽

2005 ◽

Vol 2005 (3) ◽

pp. 147-154 ◽

Cited By ~ 7

Author(s):

Etify A. Bakhite ◽

Abdu E. Abdel-Rahman ◽

Elham A. Al-Taifi

Keyword(s):

Acetic Acid ◽

Acetic Anhydride ◽

Formic Acid ◽

Hydrazine Hydrate ◽

Methyl Iodide ◽

Phosphorus Oxychloride ◽

Diethyl Malonate ◽

Triethyl Orthoformate ◽

Dimroth Rearrangement ◽

Ethyl Chloroacetate

3-amino-6-(2-thienyl)-4-trifluoromethylthieno[2,3-b]pyridine-2-carboxamide (3) and 2-carbonitrile analogue 5 were prepared by reaction of 3-cyano-6-(2-thienyl)-4-trifluoromethylpyridine-2(1H)-thione (1) with chloroacetamide or chloroacetonitrile respectively. Heating compound 3 with triethyl orthoformate led to the formation of pyridothienopyrimidinone derivative 6. Reaction of 6 with phosphorus oxychloride produced 4-chloropyrimidine derivative 7 which underwent some nucleophilic displacements upon treatment with thiourea, piperidine, morpholine or hydrazine hydrate to give the target 4-substituted pyridothienopyrimidines 8, 10a, 10b and 11 respectively. Reaction of compound 8 with methyl iodide or ethyl chloroacetate gave compounds 9a,b. The condensation of 3-amino-6-(2-thienyl)-4-trifluoromethyl-thieno[2,3-b]pyridine-2-carbonitrile (5) with triethyl orthoformate led to the formation of methanimidate derivative 21 which upon treatment with hydrazine hydrate gave the target 3-amino-3,4-dihydro-4-imino-7-(2-thienyl)-9-trifluoromethylpyrido[3′,2′:4,5] thieno[3,2-d]pyrimidine (22). The reactions of compounds 11 and 22 with some reagents namely; triethyl orthoformate, acetic anhydride, formic acid, acetic acid, acetylacetone benzaldehyde and/or diethyl malonate were carried out and their products were identified, in most cases as [1,2,4]triazolopyridothienopyrimidines via Dimroth rearrangement.

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