Synthesis of Pyrazolo[1,5‐a][1,3,5]triazine, Pyrazolo[1,5‐a]pyrimidine, and Imidazo[1,2‐b]pyrazole Derivatives Based on Imidazo[2,1‐b]thiazole Moiety

Dawood, Kamal M.; Sayed, Samia M.; Raslan, Mohamed A.

doi:10.1002/jhet.2836

Cited by 10 publications

(2 citation statements)

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“…3,6-Dihydro-4Hpyrazolo [3,4-d][1,2,3]triazin-4-ones 2, as one example of the diverse compound class, can be gained via diazotization of 3-amino-1H-pyrazole-4-carboxamides 1a or 3-amino-1H-pyrazole-4-carbonitriles 1b and subsequent cyclization of the intermediate diazo compounds under acidic conditions [22] (Scheme 1). The structurally related 3,7-dihydro-4H-pyrazolo [3,4d] [1,2,3]triazin-4-ones 3 (Figure 1) which are substituted in position N-7 can be obtained in the same manner as described in Scheme 1, if the substitution position R 1 in the starting 3-amino-1H-pyrazole-4-carboxamides 1a or 3-amino-1H-pyrazole-4-carbonitriles 1b is altered [26]. Furthermore, several 2,7dihydro-3H-imidazo [1,2-c]pyrazolo [4,3-e][1,2,3]triazines 4 were described.…”

Section: Introductionmentioning

confidence: 99%

“…The structurally related 3,7-dihydro-4 H -pyrazolo[3,4- d ][1,2,3]triazin-4-ones 3 ( Figure 1 ) which are substituted in position N-7 can be obtained in the same manner as described in Scheme 1 , if the substitution position R 1 in the starting 3-amino-1 H -pyrazole-4-carboxamides 1a or 3-amino-1 H -pyrazole-4-carbonitriles 1b is altered [ 26 ]. Furthermore, several 2,7-dihydro-3 H -imidazo[1,2- c ]pyrazolo[4,3- e ][1,2,3]triazines 4 were described.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

Wippert¹,

Nieger²,

Herlan³

et al. 2021

Beilstein J. Org. Chem.

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We describe the synthesis of so far synthetically not accessible 3,6-substituted-4,6-dihydro-3H-pyrazolo[3,4-d][1,2,3]triazines as nitrogen-rich heterocycles. The target compounds were obtained in five steps, including an amidation and a cyclative cleavage reaction as key reaction steps. The introduction of two side chains allowed a variation of the pyrazolo[3,4-d][1,2,3]triazine core with commercially available building blocks, enabling the extension of the protocol to gain other derivatives straightforwardly. Attempts to synthesize 3,7-substituted-4,7-dihydro-3H-pyrazolo[3,4-d][1,2,3]triazines, the regioisomers of the successfully gained 3,6-substituted 4,6-dihydro-3H-pyrazolo[3,4-d][1,2,3]triazines, were not successful under similar conditions due to the higher stability of the triazene functionality in the regioisomeric precursors and thus, the failure of the removal of the protective group.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

Wippert¹,

Nieger²,

Herlan³

et al. 2021

Beilstein J. Org. Chem.

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Regioselective synthesis and computational calculation studies of some new pyrazolyl‐pyridine and bipyridine derivatives

Farag

Kheder

Fahim

et al. 2023

Journal of Heterocyclic Chem

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Starting from 3‐oxo‐N‐(3‐pyridyl)butanamide, as key intermediate, the title compounds were synthesized in good yields. Reaction of the pyridine‐carboxamide 1 with hydrazonoyl chlorides 3a,b and with triethyl orthoformate afforded the corresponding pyrazole‐carboxamides 6a,b, and the bis‐pyridine 7, respectively. Coupling of the pyridine‐carboxamide 1 with 3‐phenylpyrazole‐5‐diazonium chloride gave the hydrazone 10 which upon heating in pyridine afforded the pyrazolo[5,1‐c]‐1,2,4‐triazine derivative 11. Reaction of the pyridine‐carboxamide 1 with arylmethylenepropanedinitrile derivatives afforded 1,3′‐bipyridines 13a–c. Structure elucidation of the newly synthesized compounds was carried out using IR, NMR spectroscopy, and mass spectrometry. The extensive theoretical and experimental mechanical studies of the pyrazole derivative 6a were in accordance with its elemental analysis, FT‐IR, NMR, and MS spectral data. Moreover, computer analyses indicated that the pyridine derivatives 13a,b predominated over the pyran derivatives 14a,b as the adducts. In addition, the optimization of compounds utilized the HF/6‐31G(d) and DFT/B3LYP/6‐31G(d) basis sets. Furthermore, the physical descriptors of these compounds demonstrated their stability, and NMR correlation investigations were also carried out.

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Synthesis of Polyfunctionalized Fused Pyrazolo‐Pyridines: Characterization, Anticancer Activity, Protein Binding and Molecular Docking Studies

Naik

Shastri

et al. 2019

ChemistrySelect

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The reaction of a multi-substituted pyrazole 1 with aryl or heteroaryl aldehydes and active methylene compounds afford unexpected pyrazolo[1,5-a]pyridine derivatives 4(a-k). Mechanism for this unexpected reaction involving reactivity of the active methylene moiety with a neighboring endocyclic NH group is proposed and structure has been established by the NMR and single crystal X-ray diffraction studies. Moreover, all the newly synthesized compounds were tested for their anticancer activity against sixty human cell lines at NCI. Among all the compounds, three scaffolds 4d, 4 h and 4k showed enhancement in anticancer activity in comparison with remaining synthesized compounds. Interestingly compound 4k was found to highly active even at a five dose concentration. The IC 50 values were determined against two cell lines MCF-7 and HepG2, the results obtained have shown promising effects against cancer cell lines. Further, the molecular docking studies revealed that substituted pyrazolo[1,5-a]pyridine derivatives are good candidates in the medicinal field.

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Synthesis of Pyrazolo[1,5‐a][1,3,5]triazine, Pyrazolo[1,5‐a]pyrimidine, and Imidazo[1,2‐b]pyrazole Derivatives Based on Imidazo[2,1‐b]thiazole Moiety

Cited by 10 publications

References 44 publications

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

Regioselective synthesis and computational calculation studies of some new pyrazolyl‐pyridine and bipyridine derivatives

Synthesis of Polyfunctionalized Fused Pyrazolo‐Pyridines: Characterization, Anticancer Activity, Protein Binding and Molecular Docking Studies

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