Simple Synthesis of Fused Thiazolo[4,5-b]pyridines through Successive SNAr Processes

Synlett ◽  
2020 ◽  
Author(s):  
Alexey M. Starosotnikov ◽  
Maxim A. Bastrakov ◽  
Vadim V. Kachala ◽  
Ivan V. Fedyanin ◽  
Tatyana A. Klimova ◽  
...  

AbstractA convenient process is described for the synthesis of novel thiazolo[4,5-b]pyridines fused with triazole or pyrimidine rings. The base-promoted reactions of 2-chloro-3-nitropyridines with 1,3-(S,N)-binucleophiles (triazole-5-thiols, 4-oxopyrimidine-2-thiones) resulted in nucleophilic substitution of the chlorine atom and subsequent S–N-type Smiles rearrangement followed by nucleophilic substitution of the nitro group. Reactions with pyrimidine-2-thiones were carried out as one-pot processes while, in the case of triazole-5-thiols, isolation of intermediate substitution products was found to be preferable.

Synthesis ◽  
2020 ◽  
Vol 53 (01) ◽  
pp. 175-181
Author(s):  
Mieczysław Mąkosza ◽  
Małgorzata Bechcicka ◽  
Krzysztof Wojciechowski

Acetals of dimethyl phenyl- and heteroaryl-α-hydroxymethanephosphonates were deprotonated to generate carbanions, which enter the vicarious nucleophilic substitution (VNS) of hydrogen in aromatic nitro compounds to form 4-nitrobenzhydrylphosphonates and α-heteroaryl-4-nitrobenzylphosphonates. Similarly acetals of cyano­hydrins of heteroaromatic aldehydes (furfural and 2-formylthiophene) react to form heteroaryl 4-nitroarylacetonitriles. The anion of the hemiacetal of acetaldehyde is an efficient leaving group in the base-induced β-elimination step – the crucial step in the VNS reaction. The reaction selectively occurred at the para-position to the nitro group.


2020 ◽  
Vol 24 (15) ◽  
pp. 1663-1668
Author(s):  
Dmitriy Yurievich Direnko ◽  
Boris Ivanovich Drevko ◽  
Yaroslav Borisovich Drevko

We have explored the reactions of tetrahydro-4H-selenochromenes in the presence of phosphoric pentachloride, and synthesized new condensate aroylbenzoselenophenes. During the reactions, tetrahydro-4H-selenochromenes with phosphoric pentachloride underwent oxidative aromatization and nucleophilic substitution for a chlorine atom of one of the protons in the alicyclic fragment. Also, the narrowing of the heterocyclic fragment occurred as in synthesized selenium-containing compounds earlier transformed into the corresponding condensate aroylbenzoselenophenes.


2008 ◽  
Vol 86 (7) ◽  
pp. 682-685 ◽  
Author(s):  
Barbara Szpakiewicz ◽  
Maria Grzegożek

3-, 5-, 6-, 7- and 8-Nitroquinolines react with 4-amino-1,2,4-triazole in basic medium (potassium tert-butoxide-dimethyl sulfoxide) giving amino products of the vicarious nucleophilic substitution (VNS) of hydrogen, predominantly at ortho position to the nitro group, except 8-nitroquinoline, which reacts at para position. Additionally, furazano[3,4-f]- and furazano[3,4-h]quinoline were obtained in the case of 5- and 8- nitroquinoline, respectively. 2-Nitroquinoline was aminated to 2-quinolino(1,2,4-triazol-4-yl)amine in these conditions.Key words: nitroquinolines, vicarious nucleophilic substitution (VNS), 4-amino-1,2,4-triazole.


2017 ◽  
Vol 4 (1) ◽  
pp. 11-24
Author(s):  
E. N. Ulomsky ◽  
D. N. Lyapustin ◽  
V. V. Fedotov ◽  
O. S. El'tsov ◽  
I. M. Sapozhnikova ◽  
...  

Synthesis ◽  
2018 ◽  
Vol 51 (02) ◽  
pp. 530-537 ◽  
Author(s):  
Moisés Romero-Ortega ◽  
Michelle Trujillo-Lagunas ◽  
Ignacio Medina-Mercado ◽  
Ivann Zaragoza-Galicia ◽  
Horacio Olivo

A convenient two-step, one-pot synthesis of 4-chloro-2-(trichloromethyl)pyrimidines starting from 2-(trichloromethyl)-1,3-diazabutadienes is described. These nitrogen heterocycles were prepared by a sequential acylation/intramolecular cyclization reaction between 2-(trichloromethyl)-1,3-diazabutadienes and acyl chlorides in the presence of triethylamine followed by treatment with POCl3. This is the first report for the synthesis of this type of 4-chloro-2-(trichloromethyl)pyrimidine derivatives and serves as a source for a wide variety of other substituted pyrimidines by nucleophilic substitution reactions.


Synthesis ◽  
2020 ◽  
Author(s):  
Zbigniew Wróbel ◽  
Michał Tryniszewski ◽  
Robert Bujok ◽  
Roman Gańczarczyk

Tributyl- or triphenylphosphine promotes a one-pot, three-step method for the synthesis of differently substituted dibenzodiazepinones from N-aryl-2-nitroanilines. Pyridine analogues and the corresponding thiazepinones can also be formed using this method. The process involves deoxygenation of the nitro group, then formation of an iminophosphorane intermediate and its intramolecular condensation with a carboxyl group placed in the N-aryl group. The role of the carboxyl group in the formation of the iminophosphorane and the mode of cyclization are discussed.


2020 ◽  
Vol 56 (8) ◽  
pp. 1100-1102
Author(s):  
Ani H. Hasratyan ◽  
Astkhik А. Sukoyan ◽  
Aleksan G. Shakhatuni ◽  
Gevorg G. Danagulyan ◽  
Hovhannes S. Attaryan

The Analyst ◽  
2019 ◽  
Vol 144 (24) ◽  
pp. 7283-7289 ◽  
Author(s):  
Yuan-Fei Gao ◽  
Xing Jin ◽  
Fen-Ying Kong ◽  
Zhong-Xia Wang ◽  
Wei Wang

In this contribution, highly fluorescent actinian nickel-doped carbon nanoflowers were successfully synthesized by one-step traditional hydrothermal method and allowed the analysis of quercetin in a very facile method.


Synlett ◽  
2010 ◽  
Vol 2010 (11) ◽  
pp. 1606-1608 ◽  
Author(s):  
Mehdi Adib ◽  
Hamid Bijanzadeh ◽  
Ali Mohamadi ◽  
Ehsan Sheikhi ◽  
Samira Ansari

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