Organophosphorus compounds. XX. Approaches to the synthesis of 2,3-Dihydro-1H-1,2-benzazaphospholes involving C-C and C-P ring closure

Reaction of chloromethylphosphonic dichloride (9) with N-methylaniline gave N,N'-dimethyl-N,N'-diphenylchloromethylphosphonodiarnide (10) which upon treatment with aluminium chloride underwent intramolecular Friedel-Crafts alkylation to afford 1-methyl-2-(N'-methyl-N'-phenylamino)-2,3-dihydro-1N-l,2-benzazaphosphole 2-oxide(13a). Similarly, N-methyl-N-phenyl(ch1oromethy1)phenylphosphinamide (15) was cyclized to give 1-methyl-2-phenyl-2,3-dihydro-1H-1,2-benzazaphosphole2-oxide (1 3b). Some unsuccessful approaches to this heterocyclic ring system are also reported.

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Synthesis of Novel N-Heterocyclic Compounds Containing 1,2,3-Triazole Ring System via Domino, “Click” and RDA Reactions

Molecules ◽

10.3390/molecules24040772 ◽

2019 ◽

Vol 24 (4) ◽

pp. 772 ◽

Cited By ~ 1

Author(s):

Márta Palkó ◽

Mohamed El Haimer ◽

Zsanett Kormányos ◽

Ferenc Fülöp

Keyword(s):

Heterocyclic Compounds ◽

Click Reaction ◽

Triazole Ring ◽

Heterocyclic Ring ◽

Ring System ◽

Diels Alder ◽

Ring Closure ◽

Synthetic Route ◽

13C Nuclear Magnetic Resonance ◽

Nmr Methods

An uncomplicated, high-yielding synthetic route has been developed to constitute complicated heterocycles, applying domino, click and retro-Diels–Alder (RDA) reaction sequences. Starting from 2-aminocarboxamides, a new set of isoindolo[2,1-a]quinazolinones was synthesized with domino ring closure. A click reaction was performed to create the 1,2,3-triazole heterocyclic ring, followed by an RDA reaction resulting in dihydropyrimido[2,1-a]isoindole-2,6-diones. The absolute configuration, concluded by the norbornene structure that served as a chiral source, remained constant throughout the transformations. The structure of the synthesized compounds was examined by 1H and 13C Nuclear Magnetic Resonance (NMR) methods.

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Tele-Substitution Reactions in the Synthesis of a Promising Class of Antimalarials

10.26434/chemrxiv.12212927 ◽

2020 ◽

Author(s):

Marat Korsik ◽

Edwin Tse ◽

David Smith ◽

William Lewis ◽

Peter J. Rutledge ◽

...

Keyword(s):

Heterocyclic Ring ◽

Ring System ◽

Substitution Reactions ◽

Laboratory Notebook ◽

Polar Solvents ◽

X Ray ◽

X Ray Crystallography ◽

The Core ◽

Nmr Data

We have discovered and studied a telesubstitution reaction in a biologically important heterocyclic ring system. Conditions that favour the tele-substitution pathway were identified: the use of increased equivalents of the nucleophile or decreased equivalents of base, or the use of softer nucleophiles, less polar solvents and larger halogens on the electrophile. Using results from X-ray crystallography and isotope labelling experiments a mechanism for this unusual transformation is proposed. We focused on this triazolopyrazine as it is the core structure of the in vivo active anti-plasmodium compounds of Series 4 of the Open Source Malaria consortium. Archive of the electronic laboratory notebook with the description of all conducted experiments and raw NMR data could be accessed via following link <a href="https://ses.library.usyd.edu.au/handle/2123/21890">https://ses.library.usyd.edu.au/handle/2123/21890</a> . For navigation between entries of laboratory notebook please use file "Strings for compounds in the article.pdf" that works as a reference between article codes and notebook codes, also this file contain SMILES for these compounds.

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The Chemistry of Triazine Isomers: Structures, Reactions, Synthesis and Applications

Mini-Reviews in Medicinal Chemistry ◽

10.2174/1389557520666200729160720 ◽

2020 ◽

Vol 20 ◽

Author(s):

Neelottama Kushwaha ◽

C S Sharma

Keyword(s):

Basic Property ◽

Electrophilic Substitution ◽

Antimicrobial Agents ◽

Resonance Energy ◽

Heterocyclic Ring ◽

Ring System ◽

Agricultural Fields ◽

Substitution Reactions ◽

Anti Cancer ◽

Benzene Structure

: Triazine is the six-membered heterocyclic ring containing three nitrogen which replaces carbon-hydrogen unit in the benzene ring. Based on nitrogen position present in the ring system, it is categorized in three isomeric forms i.e.1, 2, 3-triazine (vicinal triazine), 1, 2, 4-triazine (asymmetrical triazine or isotriazine) and 1, 3, 5-triazine (symmetrical or s-triazine or cyanidine). Triazines have weakly basic property. Its isomers have much weaker resonance energy than benzene structure, so nucleophilic substitution reactions are more preferred than electrophilic substitution reactions. Triazine isomers and their derivatives are known to play important roles possessing various activities in medicinal and agricultural fields such as anti-cancer, antiviral, fungicidal, insecticidal, bactericidal, herbicidal, antimalarial and antimicrobial agents.

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Resolving the Mystery of Ring Opening in the Synthesis of Benzo[d][1, 3]oxazin-4-one and Quinazolin-4(3H)-one

Letters in Organic Chemistry ◽

10.2174/1570178616666181217114030 ◽

2019 ◽

Vol 16 (11) ◽

pp. 898-905

Author(s):

Harun Patel ◽

Rahul Pawara ◽

Sanjay Surana

Keyword(s):

Characteristic Feature ◽

Ring Opening ◽

Biological Activities ◽

Heterocyclic Ring ◽

Ring System ◽

Time Saving ◽

Fusion Strategy ◽

Good Template ◽

Lead Generation

Quinazoline is the six-membered heterocyclic ring system reported for its versatile biological activities. This characteristic feature of quinazoline makes it a good template for a lead generation library. Ring opening is one of the major concerns in the synthesis of quinazolin-4(3H)-one that results in diamide formation. Here, alternative fusion strategy is reported, which is a time-saving and costeffective method to overcome the ring opening problem associated with the synthesis of benzo[ d][1,3]oxazin-4-one and quinazolin-4(3H)-one.

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A new heterocyclic ring closure in ferricyanide oxidation of 2,4,6-triphenylpyridinium salts

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19833307 ◽

1983 ◽

Vol 48 (11) ◽

pp. 3307-3314 ◽

Cited By ~ 6

Author(s):

Petr Nesvadba ◽

Petr Štrop ◽

Josef Kuthan

Keyword(s):

Alkaline Solution ◽

Heterocyclic Ring ◽

Potassium Ferricyanide ◽

Probable Mechanism ◽

Ring Closure ◽

Pyridinium Salts ◽

Mechanism Of Formation ◽

Pyrrole Derivatives ◽

Quaternary Pyridinium Salts ◽

Heterocyclic Derivatives

The quaternary pyridinium salts Ia-Ic react with alkaline solution of potassium ferricyanide to give the condensed heterocyclic derivatives IIIa, b, IV, whereas the salts Id-If give the pyrrole derivatives IIa-IIc under the same conditions. The diaza heterocycle IIIa reacts with methyl iodide to give methoiodide V, whereas by action of bromine it produces two monobromo derivatives VIa, b. The pyrrole derivatives IIa, b give monobromo derivatives IId, e on bromination. A probable mechanism of formation of the heterocyclic derivatives is discussed.

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Pyrido [2,3-d] thieno [3,2-b] [6H]thiopyran - ein neues heterocyclisches Ringsystem [1] / Pyrido [2,3-d]thieno[3,2-b] [6 H]thiopyran - a New Heterocyclic Ring System [1]

Zeitschrift für Naturforschung B ◽

10.1515/znb-1979-1118 ◽

1979 ◽

Vol 34 (11) ◽

pp. 1573-1575 ◽

Cited By ~ 5

Author(s):

Klaus Beelitz ◽

Klaus Praefcke ◽

Salo Gronowitz

Keyword(s):

Uv Irradiation ◽

Benzene Solution ◽

Heterocyclic Ring ◽

Ring System ◽

Spectroscopic Methods ◽

System 1

Abstract UV irradiation of S-(3′-thienyl)2-chloro-thionicotinate (1) in benzene solution leads via dehydrohalogenation and cy clization in competition to α-cleavage to formation of thio-lactone 2 besides aldehyde 3 and disulphide 4. 2 contains a new heterocyclic ring system which has been confirmed by spectroscopic methods.

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