Synthesis of [1,2,4]-triazolo[1,5-a]pyrimidines by Dimroth rearrangement of [1,2,4]-triazolo[4,3-a]pyrimidines: A theoretical and NMR study

Salgado, Antonio; Varela, Carmen; Collazo, Ana; Garcı́a, Fernando; Pevarello, Paolo; Alkorta, Ibón; Elguero, José

doi:10.1016/j.molstruc.2010.11.054

Cited by 28 publications

(13 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is well‐known that such Dimroth‐type process can be accomplished by heating with acid or base and is facilitated in case of electron‐withdrawing groups introduced into pyridine ring ,. In some cases the rearrangement of pyridine or pyrimidine derivatives occurs under relatively mild conditions, however, in the presence of nucleophiles, such as H 2 O or NH 3 . We found that this interconversion proceeds at room temperature ( 3 f , Scheme 6 and m , Scheme ) as well as on heating in POCl 3 (106 °C, method A ) or in acetic acid (118 °C, method B ).…”

Section: Resultsmentioning

confidence: 96%

Synthesis of N‐Bridged 6,8‐Dinitrotriazolo[1,5‐a]pyridines

et al. 2019

View full text Add to dashboard Cite

Facile and efficient protocols for the synthesis of 2- R-6,8-dinitro [1,2,4]triazolo[1,5-a]pyridines from commercially available starting materials have been developed. The reactions proceed via cyclization of corresponding 3,5-dinitropyridine-2-yl hydrazides or aldehyde 3,5-dinitropyridine-2-yl hydrazones followed by in situ Dimroth rearrangement to provide these triazole fused bicyclic heterocycles in good yields under mild conditions. Another synthetic route to target N-bridged dinitro [1,2,4] triazolo [1,5-a]pyridines includes arylation of 5-aryltetrazoles with 2-chloro-3,5-dinitropyridine and subsequent thermal decomposition/cyclization.

show abstract

Section: Resultsmentioning

confidence: 96%

Synthesis of N‐Bridged 6,8‐Dinitrotriazolo[1,5‐a]pyridines

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Recently, some [1,2,4]triazolo[1,5‐ a ]pyrimidines‐7‐amines were found to have marked anticancer activity. These scaffolds have been reported to be synthesized via a lengthy multistep procedure utilizing 8‐butyrolactone as a starting material or introducing the isomeric [1,2,4]triazolo[4,3‐ a ]pyrimidines into a formal Dimorth rearrangement with diamines under heating in basic medium .…”

Section: Introductionmentioning

confidence: 99%

Synthesis of New [1,2,4]Triazolo[1,5‐a]pyrimidine Derivatives: Reactivity of 3‐Amino[1,2,4]triazole towards Enaminonitriles and Enaminones

Alnajjar

Abdelkhalik

Raslan

et al. 2018

Journal of Heterocyclic Chem

View full text Add to dashboard Cite

A diversity of new 7-substituted[1,2,4]triazolo[1,5-a]pyrimidine and 6-substituted[1,2,4]triazolo[1,5-a] pyrimidine-7-amine derivatives has been synthesized via reaction of 3-amino-[1,2,4]triazole with enaminonitriles and enaminones. The regio orientation and the structure of the products were confirmed by spectral and analytical data and synthesis via an alternative route. The procedure proved to be simple, efficient, and high yielding, and diversities of [1,2,4]triazolo[1,5-a]pyrimidines were obtained.

show abstract

“…The chemistry of 1,2,4-triazolo [1,5- 4 activities also are documented. The more related route to 1,2,4-triazolo [1,5-a]pyrimidine is by use of unsymmetrical vinylogous iminium salts 5 .…”

Section: Introductionmentioning

confidence: 99%