Oxidative Aromatization of 4,7-Dihydro-6-nitroazolo[1,5-a]pyrimidines: Synthetic Possibilities and Limitations, Mechanism of Destruction, and the Theoretical and Experimental Substantiation

Lyapustin, Daniil N.; Ulomsky, E. N.; Balyakin, I. A.; Shchepochkin, Alexander V.; Русинов, В. Л.; Чупахин, О. Н.

doi:10.3390/molecules26164719

Cited by 7 publications

(4 citation statements)

References 57 publications

(56 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Acetic anhydride was used to activate substrate 12b as with CDI, 4-cyanodihydroisoquinolones 19a , b ( Scheme 3 ) were exclusively obtained in moderate yield, presumably, via the oxidation of the respective α-carbanion (formed, in turn, from the initial tetrahydroisoquinolone adduct due to the basic character of imidazole generated from CDI). Interestingly, thorough exclusion of air from the reaction medium by argon purging did not suppress this process, which is likely due to the possibility of nitro compounds self-oxidizing [ 19 ]. Likewise, variation in such reaction parameters as temperature, reaction duration and concentration in compound 19a synthesis did not dramatically alter the outcome of the reaction with CDI.…”

Section: Resultsmentioning

confidence: 99%

Extending the Scope of the New Variant of the Castagnoli–Cushman Cyclocondensation onto o-Methyl Benzoic Acids Bearing Various Electron-Withdrawing Groups in the α-Position

et al. 2022

View full text Add to dashboard Cite

Based on the previously reported involvement of homophthalic acid monoesters in the Castagnoli–Cushman reaction-type cyclocondensation with imines, we tested a number of other o-methyl benzoic acids bearing various electron-withdrawing groups in the α-position. The majority of these substrates delivered the expected tetrahydroisoquinolone adducts on activation with CDI or acetic anhydride. Homophthalic acid mononitriles displayed the highest promise as substrates for the new reaction, both in terms of scope and product yields. Homophthalic acid monoamides either gave low yields or failed to react with imines. Sulfonyl-substituted substrates gave the desired (and hitherto unknown) type of tetrahydroisoquinolines. Despite the low yields, this approach to sulfonyl-substituted tetrahydroisoquinolines appears practical as alternative syntheses based on the traditional, carboxylic acid CCR adducts would presumably be cumbersome and multistep. The azido- and nitro-substituted o-methyl benzoic acids failed to react with imines.

show abstract

Section: Resultsmentioning

confidence: 99%

Extending the Scope of the New Variant of the Castagnoli–Cushman Cyclocondensation onto o-Methyl Benzoic Acids Bearing Various Electron-Withdrawing Groups in the α-Position

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Pogaku et al [101] reported the synthesis of a newly designed series of benzo Recently, Lyapustin et al [102] reported the synthesis of 4,7dihydro-6-nitrotriazolo[1,5-a]pyrimidines derivatives 137 (42-65 %) based on the multicomponent process between substituted 3-aminotriazoles, 1-morpholino-2-nitroalkenes, and aldehydes in the presence of boron trifluoride etherate as acid catalyst using n-butanol as solvent (Scheme 92).…”

Section: Chemistryselectmentioning

confidence: 99%

Different Synthetic Methods for the Preparation of Triazolopyrimidines and their Biological Profile

et al. 2023

View full text Add to dashboard Cite

One or more nitrogen‐containing molecules constitute an important class of heterocyclic compounds in organic synthesis, due to their reactivity and their presence in many molecules of natural, human or plant origin. These nitrogenous heterocycles play an essential role in various scientific domains, whether they are chemical, biological or pharmacological. N‐heterocycles are the privileged source of many research topics developed by several groups of researchers. Thus, different methods have been developed to access these heterocyclic compounds with nitrogenous rings, such as triazolopyrimidines. In this review, a bibliographic study summarizing the pharmacological importance of the triazolo[1,5‐a]pyrimidine ring, the different synthesis routes of these derivatives as well as their reactivity was reported.

show abstract

“…It should be noted that compounds substituted on the N atom of the pyrimidine ring are not reduced under these conditions. [70] A common property of the dihydro derivatives of azolopyrimidines is their ability to heteroaromatize, which can be achieved preparatively by the action of Nbromosuccinimide, [16,18,19,34,35,56,64,66,[73][74][75] Br 2 /HOAc, [35,60,76,77] I 2 , [78] SeO 2 , [35] PhI(OAc) 2 , [79] CrO 3 , [80] NaNO 2 /HOAc (R 1= COOEt), [81] 2,3-dicyano-5,6-dichloro-pbenzoquinone, [72,82,83] Na 2 S 2 O 8 , [84] ammonium cerium (IV) nitrate, [85] potassium permanganate, [86] manganese (IV) oxide [50] (reaction l). Sometimes the dehydration of dihydro derivatives (reaction I) can occur as a secondary process during their synthesis.…”

Section: Chemical Properties Of Dihydroazolopyrimidinesmentioning

confidence: 99%

Dihydroazolopyrimidines: Past, Present and Perspectives in Synthesis, Green Chemistry and Drug Discovery

Desenko,

Gorobets,

Lipson

et al. 2023

The Chemical Record

View full text Add to dashboard Cite

Dihydroazolopyrimidines are an important class of heterocycles that are isosteric to natural purines and are therefore of great interest primarily as drug‐like molecules. In contrast to the heteroaromatic analogs, synthetic approaches to these compounds were developed much later, and their chemical properties and biological activity have not been studied in detail until recently. In the review, different ways to build dihydroazolopyrimidine systems from different building blocks are described – via the initial formation of a partially hydrogenated pyrimidine ring or an azole ring, as well as a one‐pot assembly of azole and azine fragments. Special attention is given to modern approaches: multicomponent reactions, green chemistry, and the use of non‐classical activation methods. Information on the chemical properties of dihydroazolopyrimidines and the prospects for their use in the design of drugs of various profiles are also summarized in this review.

show abstract

Oxidative Aromatization of 4,7-Dihydro-6-nitroazolo[1,5-a]pyrimidines: Synthetic Possibilities and Limitations, Mechanism of Destruction, and the Theoretical and Experimental Substantiation

Cited by 7 publications

References 57 publications

Extending the Scope of the New Variant of the Castagnoli–Cushman Cyclocondensation onto o-Methyl Benzoic Acids Bearing Various Electron-Withdrawing Groups in the α-Position

Extending the Scope of the New Variant of the Castagnoli–Cushman Cyclocondensation onto o-Methyl Benzoic Acids Bearing Various Electron-Withdrawing Groups in the α-Position

Different Synthetic Methods for the Preparation of Triazolopyrimidines and their Biological Profile

Dihydroazolopyrimidines: Past, Present and Perspectives in Synthesis, Green Chemistry and Drug Discovery

Contact Info

Product

Resources

About