Untitled

Теренин, В. И.; Kabanova, E. V.; Tselishcheva, N. A.; Kovalkina, M. A.; Плешкова, А. П.; Зык, Н. В.

doi:10.1023/a:1002876901829

Cited by 5 publications

(2 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[207,208] and dipyrrolo[1,2-a;2',1'-c]pyrazines [209][210][211][212][213][214][215][216] in electrophilic substitution reactions (protonation, acylation, aminomethylation, nitration, formylation, phosphorylation) was investigated systematically. [207,208] and dipyrrolo[1,2-a;2',1'-c]pyrazines [209][210][211][212][213][214][215][216] in electrophilic substitution reactions (protonation, acylation, aminomethylation, nitration, formylation, phosphorylation) was investigated systematically.…”

Section: Rshmentioning

confidence: 99%

Chemistry of heterocyclic compounds at the Department of Organic Chemistry, Chemical Faculty, M. V. Lomonosov State University. (Review)

Yurovskaya

2005

Chem Heterocycl Compd

View full text Add to dashboard Cite

show abstract

Section: Rshmentioning

confidence: 99%

Chemistry of heterocyclic compounds at the Department of Organic Chemistry, Chemical Faculty, M. V. Lomonosov State University. (Review)

Yurovskaya

2005

Chem Heterocycl Compd

View full text Add to dashboard Cite

show abstract

“…It was found that the reaction occurs nonspecifically and the result is governed by the structure of the starting substrates [2].…”

mentioning

confidence: 99%

Formylation of pyrrolo-[1,2-a]pyrazines

Теренин

Butkevich

Иванов

et al. 2008

Chem Heterocycl Comp

Self Cite

View full text Add to dashboard Cite

The formylation of pyrrolo [1,2-a]pyrazines containing alkyl, aryl, or hetaryl substituents in positions 1 and 6 of the heterocycle has been studied. It has been shown that formylation of 1-phenyl-and 1-(2 thienyl)pyrrolo [1,2-a]pyrazine occurs selectively at the α-position of the pyrrole ring. In all of the remaining examples the reaction course depends on substituent, reagent ratio, and reaction time.The broad spectrum of biological activity of heteroaromatic polycyclic systems with a common bridging nitrogen atom and containing a pyrrole ring is the basis for the continuing interest in the synthesis of this class of compounds. One such structure is the aromatic pyrrolo[1,2-a]pyrazine bicyclic system which contains both a π-electron-rich pyrrole ring and a π-electron-deficient pyrazine ring.Within the scope of a systematic investigation of electrophilic reactions in such a series of compounds we have studied the formylation of 1-and 6-alkyl-, aryl-, and hetaryl-substituted pyrrolo[1,2-a]pyrazines 1a-g.It is known that unsubstituted pyrrolo[1,2-a]pyrazine is formylated at the β'-position of the pyrrole ring in 60% yield [1]. However, the 1 H NMR spectrum of this compound reported by the authors casts doubt upon the correctness of this structural identification. The low field shift of the H-4 proton signal (9.38 ppm) points to α-rather than β'-formylation.In our laboratory we have also previously studied the formylation of the 3,4-dihydro analogs of pyrrolo[1,2-a]pyrazines. It was found that the reaction occurs nonspecifically and the result is governed by the structure of the starting substrates [2].We have found that in the case of 1-substituted aromatic pyrrolo[1,2-a]pyrazines only 1-phenylpyrrolo[1,2-a]pyrazine (1a) and 1-(2-thienyl)pyrrolo[1,2-a]pyrazine (1b) are selectively formylated to give the 6-formyl derivatives 2a and 2b respectively.The low field shift of the pyrazine proton signal at position 4 in the formylated products when compared with the starting 1-phenyl-and 1-(2-thienyl)pyrrolo[1,2-a]pyrazines (9.44 and 9.39 ppm compared with 7.75 and 7.64 ppm respectively) indicates that the formyl group occurs at position 6 of the heterocycles. N R N N R N H O POCl 3 1a,b 2a,b DMF 0-20°C 1, 2 a R = Ph, b R = 2-thienyl __________________________________________________________________________________________

show abstract

Formylation of 3,4‐Dihydropyrrolo[1,2‐a]pyrazines.

et al. 2001

View full text Add to dashboard Cite

Formylation of 3,4-Dihydropyrrolo[1,2-a]pyrazines. -The direction of the Vilsmeier formylation of the title heterocycles [cf. (I), (V), (VII)] is shown to depend on the substitution pattern of the starting material. Formylation of 1-methyl-substituted dihydropyrrolopyrazines (I) occurs selectively at the methyl group. -(TERENIN, V. I.; TSELISHCHEVA, N. A.; KABANOVA, E. V.; PLESHKOVA, A. P.; ZYK, N. V.; Chem. Heterocycl.

show abstract

Untitled

Cited by 5 publications

References 6 publications

Chemistry of heterocyclic compounds at the Department of Organic Chemistry, Chemical Faculty, M. V. Lomonosov State University. (Review)

Chemistry of heterocyclic compounds at the Department of Organic Chemistry, Chemical Faculty, M. V. Lomonosov State University. (Review)

Formylation of pyrrolo-[1,2-a]pyrazines

Formylation of 3,4‐Dihydropyrrolo[1,2‐a]pyrazines.

Contact Info

Product

Resources

About