scholarly journals A Suitable Functionalization of Nitroindazoles with Triazolyl and Pyrazolyl Moieties via Cycloaddition Reactions

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 126
Author(s):  
Mohammed Eddahmi ◽  
Nuno M. M. Moura ◽  
Latifa Bouissane ◽  
Ouafa Amiri ◽  
M. Amparo F. Faustino ◽  
...  
Keyword(s):  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Nitrile Imines

The alkylation of a series of nitroindazole derivatives with 1,2-dibromoethane afforded the corresponding N-(2-bromoethyl)- and N-vinyl-nitro-1H-indazoles. The Cu(I)-catalysed azide- alkyne 1,3-dipolar cycloaddition was selected to substitute the nitroindazole core with 1,4-disubstituted triazole units after converting one of the N-(2-bromoethyl)nitroindazoles into the corresponding azide. The reactivity in 1,3-dipolar cycloaddition reactions with nitrile imines generated in situ from ethyl hydrazono-α-bromoglyoxylates was studied with nitroindazoles bearing a vinyl unit. The corresponding nitroindazole-pyrazoline derivatives were obtained in good to excellent yields.

A Convenient Synthesis of Tetrasubstituted Pyrazoles from Nitrile Imines and 2-(Thioxothiazolidin-5-ylidene)acetates

Synlett ◽  
2018 ◽  
Vol 29 (07) ◽  
pp. 918-921 ◽  
Author(s):  
Issa Yavari ◽  
Zohreh Taheri ◽  
Maryam Naeimabadi ◽  
Samira Bahemmat ◽  
Mohammad Halvagar
Keyword(s):  
Double Bond ◽  
Dipolar Cycloaddition ◽  
Pyrazole Derivatives ◽  
X Ray ◽  
X Ray Crystallography ◽  
Hydrazonoyl Chlorides ◽  
Convenient Synthesis ◽  
Nitrile Imines ◽  
Fast Access

Alkyl 2-(3-alkyl-4-oxo-2-thioxothiazolidin-5-ylidene)acetates react with hydrazonoyl chlorides in the presence of triethylamine to ­afford tetrasubstituted pyrazole derivatives. Formally, this transformation is regarded as a 1,3-dipolar cycloaddition of the exocyclic carbon–carbon double bond of the thioxothiazolidine derivatives with nitrile imines generated in situ. This efficient method provides fast access to a range of structurally diverse pyrazoles. The structure of a typical product is confirmed by X-ray crystallography.

scholarly journals Synthesis of Dispiro[Indeno[1,2-b]Quinoxaline-11,3′-Pyrrolizine-2′,2″-[1,3] Thiazolo[3,2-a]Pyrimidine Via Cycloaddition Reactions

2018 ◽  
Vol 42 (9) ◽  
pp. 453-455 ◽  
Author(s):  
Demin Ren ◽  
Xiaolian Hu ◽  
Yulin Huang ◽  
Xiaofang Li
Keyword(s):  
Cycloaddition Reaction ◽  
Crystallographic Analysis ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
X Ray

The 1,3-dipolar cycloaddition reaction of ethyl 5-aryl-2-(2-methoxy-2-oxoethylidene)-7-methyl-3-oxo-2,3-dihydro-5 H-[1,3]thiazolo[3,2- a] pyrimidine-6-carboxylate and azomethine ylide, which was generated in situ by the reaction of 11 H-indeno[1,2- b]quinoxalin-11-one and L-proline, afforded novel 6″ethyl 1′-methyl 5″aryl-7″methyl-3″oxo-5’,6’,7’,7a′-tetrahydro-1' H,3″ H,5″ H-dispiro[indeno[1,2- b]quinoxaline-11, 3 ‘-pyrrolizine-2’,2″-[1,3]thiazolo[3,2- a]pyrimidine-1’,6″-dicarboxylates in good yields. The structures of all the products were characterised thoroughly by NMR, IR and HRMS together with X-ray crystallographic analysis.

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