Susceptibility of Methyl 3-Amino-1<i>H</i>-pyrazole-5-carboxylate to Acylation

Kusakiewicz-Dawid, Anna; Górecki, Łukasz; Masiukiewicz, Ełżbieta; Rzeszotarska, Barbara

doi:10.1080/00397910902898536

Cited by 7 publications

(5 citation statements)

References 2 publications

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“…Furthermore, Anna Kusakiewicz-Dawid reported amide formation without the protection of pyrazole by using the condensing agent DCC at room temperature [16]. Therefore, DCC and DMAP were used for direct amidation, without any protection.…”

Section: Chemistrymentioning

confidence: 99%

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Synthesis of Functionalized Thiophene Based Pyrazole Amides via Various Catalytic Approaches: Structural Features through Computational Applications and Nonlinear Optical Properties

et al. 2022

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In the present study, pyrazole-thiophene-based amide derivatives were synthesized by different methodologies. Here, 5-Bromothiophene carboxylic acid (2) was reacted with substituted, unsubstituted, and protected pyrazole to synthesize the amide. It was observed that unsubstituted amide (5-bromo-N-(5-methyl-1H-pyrazol-3-yl)thiophene-2-carboxamide (7) was obtained at a good yield of about 68 percent. The unsubstituted amide (7) was arylated through Pd (0)-catalyzed Suzuki–Miyaura cross-coupling, in the presence of tripotassium phosphate (K3PO4) as a base, and with 1,4-dioxane as a solvent. Moderate to good yields (66–81%) of newly synthesized derivatives were obtained. The geometry of the synthesized compounds (9a–9h) and other physical properties, like non-linear optical (NLO) properties, nuclear magnetic resonance (NMR), and other chemical reactivity descriptors, including the chemical hardness, electronic chemical potential, ionization potential, electron affinity, and electrophilicity index have also been calculated for the synthesized compounds. In this study, DFT calculations have been used to investigate the electronic structure of the synthesized compounds and to compute their NMR data. It was also observed that the computed NMR data manifested significant agreement with the experimental NMR results. Furthermore, compound (9f) exhibits a better non-linear optical response compared to all other compounds in the series. Based on frontier molecular orbital (FMO) analysis and the reactivity descriptors, compounds (9c) and (9h) were predicted to be the most chemically reactive, while (9d) was estimated to be the most stable among the examined series of compounds.

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Section: Chemistrymentioning

confidence: 99%

“…Ethyl acetate (50 mL) and a saturated citric acid solution (50 mL) were added to the dried reaction mixture, then the ethyl acetate layer was collected and subjected to CC, to separate the components of the reaction mixture. The synthesized product was verified using various techniques like 1 H-NMR, 13 C-NMR, and elemental analysis [16].…”

Section: 3mentioning

confidence: 99%

Synthesis of Functionalized Thiophene Based Pyrazole Amides via Various Catalytic Approaches: Structural Features through Computational Applications and Nonlinear Optical Properties

et al. 2022

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“…The studied compounds Ac-Pz-OMe (1), glycol-Pz-OMe (4), Z-Lys(Boc)-Pz-OMe (6), and Boc-Pz-OMe (8) were obtained according to literature [25,[30][31][32][33]. Glycol-Pz-NH-NH 2 (5) was synthesized on the basis of previously described procedure [34].…”

Section: Synthesismentioning

confidence: 99%

Pyrazole amino acids: hydrogen bonding directed conformations of 3-amino-1H-pyrazole-5-carboxylic acid residue

et al. 2017

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A series of model compounds containing 3-amino-1H-pyrazole-5-carboxylic acid residue with N-terminal amide/urethane and C-terminal amide/hydrazide/ester groups were investigated by using NMR, Fourier transform infrared, and single-crystal X-ray diffraction methods, additionally supported by theoretical calculations. The studies demonstrate that the most preferred is the extended conformation with torsion angles ϕ and ψ close to ±180°. The studied 1H-pyrazole with N-terminal amide/urethane and C-terminal amide/hydrazide groups solely adopts this energetically favored conformation confirming rigidity of that structural motif. However, when the C-terminal ester group is present, the second conformation with torsion angles ϕ and ψ close to ±180° and 0°, respectively, is accessible. The conformational equilibrium is observed in NMR and Fourier transform infrared studies in solution in polar environment as well as in the crystal structures of other related compounds. The observed conformational preferences are clearly related to the presence of intramolecular interactions formed within the studied residue. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

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“…The Boc-protection of a 3(5)-aminopyrazole system represents an illustrative example, where both endocyclic nitrogens and the amino groups can be protected concurrently [ 15 , 16 ]. The protection usually led to a mixture of mono- and di-substituted regio-isomers, which are difficult to purify.…”

Section: Introductionmentioning

confidence: 99%

“…To avoid that, several methods were developed: (i) the acylation of aminopyrazoles with 2 equiv. of acyl reagents followed with saponification of the acyl group attached at the endocyclic pyrazole nitrogen [ 17 ]; (ii) the oxidation-reduction sequence of the amino group including Boc-protection of the endocyclic pyrazole nitrogen [ 18 ]; and (iii) the direct Boc-protection under alkaline conditions [ 16 ].…”

Section: Introductionmentioning

confidence: 99%

Modification of Boc-Protected CAN508 via Acylation and Suzuki-Miyaura Coupling

et al. 2018

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The cyclin-dependent kinase inhibitor, CAN508, was protected with di-tert-butyl dicarbonate to access the amino-benzoylated pyrazoles. The bromo derivatives were further arylated by Suzuki-Miyaura coupling using the XPhos Pd G2 pre-catalyst. The coupling reaction provided generally the para-substituted benzoylpyrazoles in the higher yields than the meta-substituted ones. The Boc groups were only utilized as directing functionalities for the benzoylation step and were hydrolyzed under conditions of Suzuki-Miyaura coupling, which allowed for elimination of the additional deprotection step.

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Susceptibility of Methyl 3-Amino-1H-pyrazole-5-carboxylate to Acylation

Cited by 7 publications

References 2 publications

Synthesis of Functionalized Thiophene Based Pyrazole Amides via Various Catalytic Approaches: Structural Features through Computational Applications and Nonlinear Optical Properties

Synthesis of Functionalized Thiophene Based Pyrazole Amides via Various Catalytic Approaches: Structural Features through Computational Applications and Nonlinear Optical Properties

Pyrazole amino acids: hydrogen bonding directed conformations of 3-amino-1H-pyrazole-5-carboxylic acid residue

Modification of Boc-Protected CAN508 via Acylation and Suzuki-Miyaura Coupling

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