Synthesis of fully substituted pyrazoles from pyridinium 1,4-zwitterionic thiolates and hydrazonoyl chlorides via a [[3 + 3] − 1] pathway

2020 ◽  
Vol 18 (15) ◽  
pp. 2949-2955 ◽  
Author(s):  
Bin Cheng ◽  
Bian Bao ◽  
Wei Xu ◽  
Yuntong Li ◽  
Hui Li ◽  
...  
Keyword(s):  
Ring Contraction ◽  
Cascade Cyclization ◽  
Hydrazonoyl Chlorides ◽  
Substituted Pyrazoles ◽  
Extrusion Reaction

Pyrazoles were synthesized from pyridinium 1,4-zwitterionic thiolates and hydrazonoyl chlorides via an unusual [[3 + 3] − 1] pathway, involving a formal [3 + 3] cascade cyclization followed by a spontaneous ring-contraction/sulfur extrusion reaction.

Synthesis of 8,10-disubstituted-triazoloperimidines from (E)-3-(dimethylamino)-1-(8- phenyl-8H-[1,2,4]triazolo[4,3-a]perimidin-10-yl)prop-2-en-1-one and Their Antimicrobial Activity

2018 ◽  
Vol 15 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Ghada S. Masaret ◽  
Thoraya A. Farghaly
Keyword(s):  
Antimicrobial Activity ◽  
Acetic Acid ◽  
Hydrazine Hydrate ◽  
Spectral Data ◽  
Organic Compounds ◽  
The Novel ◽  
Hydrazonoyl Chlorides ◽  
Elemental Analyses ◽  
Different Types ◽  
Substituted Pyrazoles

Aim and Objective: Enaminones belay to be extremely stable compounds and constitute a versatile group of salutary precursors for the synthesis of enormous classes of organic compounds. So, in this context, we synthesized a new enaminone, namely, (E)-3-(dimethylamino)-1-(8-phenyl-8H-[1,2,4]triazolo[4,3- a]perimidin-10-yl)prop-2-en-1-one (enaminone 2). Materials and Methods: The reaction of enaminone 2 with different types of hydrazonoyl chlorides or hydrazine hydrate afforded new substituted pyrazoles. Also, the reaction of enaminone with 6-amino-2- thioxopyrimidin-4-one in acetic acid under reflux produced 2-thioxopyridopyrimidinone derivative. The latter thione derivative reacts with hydrazonoyl chlorides to give pyridotriazolopyrimidines. 5-(8-Phenyl-8H- [1,2,4]triazolo[4,3-a]perimidin-10-yl)isoxazole was produced from the reaction of enaminone 2 with hydroxylamine. Results & Conclusion: The structure of all the novel perimidine derivatives was confirmed on the basis of spectral data and elemental analyses. The enaminone and the newly synthesized compounds were tested for their antimicrobial activity, and the results obtained revealed that some derivatives are more potent than the reference drugs used.

scholarly journals When Hydrazonoyl Chlorides Meet Allenes: a Site- and Regio-Selective Copper(I)-Catalysed Approach to 5-Substituted Pyrazoles

Heterocycles ◽  
2021 ◽  
Vol 102 (10) ◽  
pp. 1995
Author(s):  
Giorgio Molteni ◽  
Stefano Baroni ◽  
Marco Manenti ◽  
Alessandra Silvani
Keyword(s):  
Hydrazonoyl Chlorides ◽  
A Site ◽  
Substituted Pyrazoles

Iodine-promoted synthesis of pyrazoles from 1,3-dicarbonyl compounds and oxamic acid thiohydrazides

2020 ◽  
Vol 7 (13) ◽  
pp. 1640-1646
Author(s):  
Anna S. Komendantova ◽  
Konstantin A. Lyssenko ◽  
Igor V. Zavarzin ◽  
Yulia A. Volkova
Keyword(s):  
Dicarbonyl Compounds ◽  
Ring Contraction ◽  
Novel Approach ◽  
Oxamic Acid Thiohydrazides ◽  
Ring Contraction Reaction ◽  
Substituted Pyrazoles

A novel approach to 3,4-dicarbonyl-substituted pyrazoles from 1,3-dicarbonyl compounds and oxamic acid thiohydrazides was developed via iodine-promoted cascade imination/halogenation/cyclization/ring contraction reaction.

TBHP promoted demethylation of α-amino carbonyl compounds: a concise approach to substituted γ-lactams

2019 ◽  
Vol 6 (11) ◽  
pp. 1837-1841 ◽  
Author(s):  
Xue Peng ◽  
Hui-Hong Wang ◽  
Fei Cao ◽  
Hong-Hua Zhang ◽  
Ying-Mei Lu ◽  
...  
Keyword(s):  
Carbonyl Compounds ◽  
Ring Contraction ◽  
Butyl Hydroperoxide ◽  
Extrusion Reaction

A novel tert-butyl hydroperoxide (TBHP) promoted CH2-extrusion reaction of α-amino carbonyl compounds has been developed, which is driven by a demethylenation process to give various ring contraction products γ-lactams under radical conditions.

Fe-Catalyzed Conjunctive Cross-Couplings of Unactivated Alkenes with Grignard Reagents

2020 ◽  
Author(s):  
Lei Liu ◽  
Wes Lee ◽  
Cassandra R. Youshaw ◽  
Mingbin Yuan ◽  
Michael B. Geherty ◽  
...  
Keyword(s):  
Functional Groups ◽  
Cross Coupling ◽  
Alkyl Halides ◽  
Grignard Reagents ◽  
Turnover Frequency ◽  
Diverse Range ◽  
Cascade Cyclization ◽  
Radical Cascade

The first iron-catalyzed three-component cross-coupling of unactivated olefins with alkyl halides and Grignard reagents is reported. The reaction operates under fast turnover frequency and tolerates a diverse range of sp2-hybridized nucleophiles, alkyl halides, and unactivated olefins bearing diverse functional groups to yield the desired 1,2-alkylarylated products with high regiocontrol. Further, we demonstrate that this protocol is amenable for the synthesis of new (hetero)carbocycles including tetrahydrofurans and pyrrolidines via a three-component radical cascade cyclization/arylation that forges three new C-C bonds.

SYNTHESIS OF NOVEL SUBSTITUTED PYRAZOLES AND ISOXAZOLES CONTAINING 1, 4-BENZODIOXANE SULFONYL MOIETY

2020 ◽  
Vol 13 (03) ◽  
pp. 1959-1963
Author(s):  
Sandhya Chhakra ◽  
G. S. Malhotra ◽  
S. Singh ◽  
S. S. Chauhan
Keyword(s):  
Substituted Pyrazoles
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