ChemInform Abstract: VILSMEIER‐HAACK REACTION OF 5‐AMINO‐ AND 5‐ACYLAMINOPYRAZOLES

Simay, Antal; Takács, Kálmán; Horváth, Károly; Dvortsak, P.

doi:10.1002/chin.198109266

Cited by 9 publications

(11 citation statements)

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“…For compounds 15 and 16 bearing ortho-and para-Cl phenyl substituents, respectively, at the N-1 position, the induction effect of the N-1 para-Cl substituent was stronger than ortho-Cl (77% vs. 72%, Table 2). All 6-[(formyloxy)methyl]-1H-pyrazolo [3,4-d]pyrimidines (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) were characterized by spectroscopic methods. The structure of 6-[(formyloxy)methyl]-1H-pyrazolo [3,4-d]pyrimidine 24 was also characterized by X-ray crystallography and the ORTEP drawing is shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Pyrazolopyrimidines can also be accessed via heterocyclization using starting materials such as 5-amino-4formypyrazoles, 22 5-amino-1H-4-pyrazolcarbonitriles, 23 and 5amino-1H-4-pyrazolcarboxamides. [23][24][25][26] However, the method for preparing pyrazolopyrimidines involves harsh conditions, long reaction times, complex synthetic procedures, and tedious purication steps. 27 Therefore, convenient synthetic routes for the synthesis of pyrimidine fused heterocyclic systems have attracted considerable attention.…”

Section: Introductionmentioning

confidence: 99%

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Vilsmeier reagent-mediated synthesis of 6-[(formyloxy)methyl]-pyrazolopyrimidines via a one-pot multiple tandem reaction

Liu

Wong

2015

RSC Adv.

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A new Vilsmeier reagent mediated one-pot reaction using 5-(2-chloroacetylamino)pyrazoles as the starting material was developed for the efficient synthesis of 6-[(formyloxy)methyl]-1H-pyrazolo[3,4-d]pyrimidine. This new multiple tandem reactions involving Vilsmeier-Haack reaction, Morgan-Walls reaction, sequential elimination, substitution reaction, and final hydrolysis reaction efficiently afforded formyloxymethyl pyrazolo[3,4-d]pyrimidine products in good yields.Morgan-Walls cyclization reaction, sequential elimination, substitution reaction, and hydrolysis for synthesis of the pyrazole fused pyrimidine derivatives via a tandem multiple reaction. 14,16Pyrimidines fused with a heterocycle such as furo-, 17 pyrazolo-, 18 pyrrolo-, 19 pyridopyrazolo-, 20 and pyrazolotriazolo-pyrimidine 21 are important classes of compounds and also currently of interest to the pharmaceutical industry due to their

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Vilsmeier reagent-mediated synthesis of 6-[(formyloxy)methyl]-pyrazolopyrimidines via a one-pot multiple tandem reaction

Liu

Wong

2015

RSC Adv.

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“…Compound 1 was reacted with DMF and phosphorus oxychloride (Vilsmeier-Haack reagent) at 70 • C for 5 h to afford intermediate 2. Subsequent refluxing of the solution of 2 and ammonium carbonate in acetic acid resulted in the formation of compound 3, 4-(3-phenyl-1H-pyrazolo [3,4-d]pyrimidin-1-yl)thieno [3,2-d]pyrimidine, in 82% yield [17].…”

Section: Resultsmentioning

confidence: 99%

4-(3-Phenyl-1H-pyrazolo[3,4-d]pyrimidin-1-yl)thieno[3,2-d]pyrimidine

Noh

Kim

Song

2020

Molbank

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A new hybrid compound, 4-(3-phenyl-1H-pyrazolo[3,4-d]pyrimidin-1-yl)thieno[3,2-d]pyrimidine 3, with promising biological activity was efficiently synthesized by the reaction of 3-phenyl-1-(thieno[3,2-d]pyrimidin-4-yl)-1H-pyrazol-5-amine with Vilsmeier–Haack reagent and subsequent treatment with ammonium carbonate. The structure of the synthesized compound was fully characterized by 1H-, 13C-NMR, IR spectroscopy, mass-spectrometry and elemental analysis.

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“…3-(4-Chlorophenyl)-1-phenyl-1H-pyrazolo[3,4-d]pyrimidi ne ( 3m ) [ 13 , 14 , 15 , 45 ]. Light-yellow solid; m.p.…”

Section: Methodsmentioning

confidence: 99%

One-Flask Synthesis of Pyrazolo[3,4-d]pyrimidines from 5-Aminopyrazoles and Mechanistic Study

et al. 2017

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A novel one-flask synthetic method was developed in which 5-aminopyrazoles were reacted with N,N-substituted amides in the presence of PBr3. Hexamethyldisilazane was then added to perform heterocyclization to produce the corresponding pyrazolo[3,4-d]pyrimidines in suitable yields. These one-flask reactions thus involved Vilsmeier amidination, imination reactions, and the sequential intermolecular heterocyclization. To study the reaction mechanism, a series of 4-formyl-1,3-diphenyl-1H-pyrazol-5-yl-N,N-disubstituted formamidines, which were conceived as the chemical equivalent of 4-(iminomethyl)-1,3-diphenyl-1H-pyrazol-5-yl-formamidine, were prepared and successfully converted into pyrazolo[3,4-d]pyrimidines. The experiments demonstrated that the reaction intermediates were the chemical equivalents of 4-(iminomethyl)-1,3-diphenyl-1H-pyrazol-5-yl)formamidines. The rate of the reaction could be described as being proportional to the reactivity of amine reactants during intermolecular heterocyclization, especially when hexamethyldisilazane was used.

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ChemInform Abstract: VILSMEIER‐HAACK REACTION OF 5‐AMINO‐ AND 5‐ACYLAMINOPYRAZOLES

Abstract: Die entsprechenden Pyrazole (Ia) oder (Ib) setzen sich mit DMF/POCI3 zu Aldehyden, wie z.B. (IV), um.

Cited by 9 publications

References 0 publications

Vilsmeier reagent-mediated synthesis of 6-[(formyloxy)methyl]-pyrazolopyrimidines via a one-pot multiple tandem reaction

Vilsmeier reagent-mediated synthesis of 6-[(formyloxy)methyl]-pyrazolopyrimidines via a one-pot multiple tandem reaction

4-(3-Phenyl-1H-pyrazolo[3,4-d]pyrimidin-1-yl)thieno[3,2-d]pyrimidine

One-Flask Synthesis of Pyrazolo[3,4-d]pyrimidines from 5-Aminopyrazoles and Mechanistic Study

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