N,N-Dialkyl-N′-Chlorosulfonyl Chloroformamidines in Heterocyclic Synthesis. Part VII 4-Dialkylamino[1,2,3,5]Benzoxathiadiazepine Dioxides and 4-Dialkylamino-[2,1,3,5]Benzothiatriazepine Dioxides

2008 ◽  
Vol 61 (10) ◽  
pp. 785 ◽  
Author(s):  
Teresa Cablewski ◽  
Craig M. Forsyth ◽  
Craig L. Francis ◽  
Andris J. Liepa ◽  
Victor Tran

N,N-dialkyl-N′-chlorosulfonyl chloroformamidines 1 reacted with 2-aminophenols 2 to give 4-dialkylamino[1,2,3,5]benzoxathiadiazepine dioxides 3, which are examples of a new ring system. Reaction of 1 with 1,2-diaminobenzenes 7 afforded 4-dialkylamino[2,1,3,5]benzothiatriazepine dioxides 8 and 9, which are new derivatives of a rare ring system. Some N-alkyl and N-acyl derivatives of 3 and 8 were prepared to demonstrate the potential of these compounds as novel scaffolds for synthetic and medicinal chemistry.

2018 ◽  
Vol 71 (1) ◽  
pp. 58 ◽  
Author(s):  
Dylan Innes ◽  
Michael V. Perkins ◽  
Andris J. Liepa ◽  
Craig L. Francis

N,N-Dialkyl-N′-chlorosulfonyl chloroformamidines 1 underwent regioselective reactions with the 1,3-NCC bis-nucleophilic 1H-benzimidazole-2-acetonitriles 4 and related compounds to produce benzo[4,5]imidazo[1,2-b][1,2,6]thiadiazine dioxides 6, 9, 12, and 14, representatives of a new ring system. Reaction of dichlorides 1 with trifluoroacetyl derivative 16 afforded benzo[4,5]imidazo[1,2-c]pyrimidines 19 and 20. An N-acyl and some N-alkyl derivatives of benzimidazo-thiadiazines 6 were prepared to demonstrate the potential of this new ring system as a novel scaffold for synthetic and medicinal chemistry applications. Treatment of the 4-cyano-5-methyl-benzimidazo-thiadiazine 26c with LiAlH4 resulted in an unexpected and remarkable conversion of the nitrile to give the 4,5-dimethyl-benzimidazo-thiadiazine 29.


1988 ◽  
Vol 41 (3) ◽  
pp. 293 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
LM Engelhardt ◽  
IWK Gunawardana ◽  
AH White

Meisenheimer rearrangement of the N-oxides (4) derived from a series of 5-aryl-4-methyl-2,3,4,5-tetrahydro-1,4-benzoxazepines (3) gave rise to eight derivatives (5) of the new 2H,6H-1,5,4-benzodioxazocine ring system. Reaction of 9-methoxy-5-methyl-6-phenyl-3,4,5,6- tetrahydro-2H-1,5-benzoxazocine (6) with 3-chloroperoxybenzoic acid gave an unstable N-oxide (7). A Meisenheimer rearrangement product from (7), 10-methoxy-5-methyl-7-phenyl-2,3,4,5-tetrahydro-7 H-1,6,5- benzodioxazonine (8), the first example of this ring system, was isolated directly in moderate yield on oxidation of (6) with cooling. The crystal and molecular structure of (8) has been determined by X-ray crystallographic methods.


2010 ◽  
Vol 63 (4) ◽  
pp. 659 ◽  
Author(s):  
Craig M. Forsyth ◽  
Craig L. Francis ◽  
Saba Jahangiri ◽  
Andris J. Liepa ◽  
Michael V. Perkins ◽  
...  

N,N-dialkyl-N′-chlorosulfonyl chloroformamidines 1 reacted with pyrazol-3-ones 2 under a variety of conditions to give pyrazolo[2,3-e][1,2,3,5]oxathiadiazine dioxides 3 and pyrazolo[3,2-b][1,4,3,5]oxathiadiazine dioxides 5, and frequently, one or both of pyrazolo[1,2-b][1,2,3,5]thiatriazole 1,1,5-trioxides 4 and 1,1,7-trioxides 6. In all reactions, the pyrazolo[3,2-b][1,4,3,5]oxathiadiazine 5 was the major product, with the pyrazolo[2,3-e][1,2,3,5]oxathiadiazine 3 being a significant product in the absence of base. Prior to our recent work, the core ring systems of compounds 3 and 5 had not been reported and compounds 4 and 6 are new derivatives of a rare ring system.


2020 ◽  
Vol 27 (40) ◽  
pp. 6864-6887 ◽  
Author(s):  
Mohd Adil Shareef ◽  
Irfan Khan ◽  
Bathini Nagendra Babu ◽  
Ahmed Kamal

Background:: Imidazo[2,1-b]thiazole, a well-known fused five-membered hetrocycle is one of the most promising and versatile moieties in the area of medicinal chemistry. Derivatives of imidazo[2,1-b]thiazole have been investigated for the development of new derivatives that exhibit diverse pharmacological activities. This fused heterocycle is also a part of a number of therapeutic agents. Objective:: To review the extensive pharmacological activities of imidazo[2,1-b]thiazole derivatives and the new molecules developed between 2000-2018 and their usefulness. Method:: Thorough literature review of all relevant papers and patents was conducted. Conclusion:: The present review, covering a number of aspects, is expected to provide useful insights in the design of imidazo[2,1-b]thiazole-based compounds and would inspire the medicinal chemists for a comprehensive and target-oriented information to achieve a major breakthrough in the development of clinically viable candidates.


Author(s):  
Ravinder Sharma ◽  
Pooja A. Chawla ◽  
Viney Chawla ◽  
Rajeev Verma ◽  
Nandita Nawal ◽  
...  

Abstract: A sizeable proportion of currently marketed drugs come from heterocycles. The heterocyclic moiety 5-pyrazolone is well known five membered ring containing nitrogen. Derivatives of this wonder nucleus have exhibited activities as diverse as antimicrobial, anti-inflammatory, analgesic, antidepressant, anticonvulsant, antidiabetic, antihyperlipidemic, antiviral, antitubercular, antioxidant, anticancer and antiviral including action against severe acute respiratory syndrome (SARS) or 3C protease inhibitor. A number of drugs based on this motif have already made it to the market. Standard texts and literature on medicinal chemistry cite different approaches for the synthesis of 5-pyrazolones. The present review provides an insight view to 5-pyrazolone synthesis, their biological profile and structure activity relationship studies.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1608
Author(s):  
Stephen Lo ◽  
Euphemia Leung ◽  
Bruno Fedrizzi ◽  
David Barker

Quercetin is a flavonoid that is found in many plant materials, including commonly eaten fruits and vegetables. The compound is well known for its wide range of biological activities. In this study, 5-O-acyl derivatives of quercetin were synthesised and assessed for their antiproliferative activity against the HCT116 colon cancer and MDA-MB-231 breast cancer cell lines; and their radical scavenging activity against the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical species. Four derivatives were found to have improved the antiproliferative activity compared to quercetin whilst retaining radical scavenging activity.


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