Synthesis of 5,7-diarylpyrazolo[1,5- a ]pyrimidines via KOH mediated tandem reaction of 1 H -pyrazol-3-amines and chalcones

Kaswan, Pinku; Pericherla, Kasiviswanadharaju; Purohit, D.M.; Kumar, Anil

doi:10.1016/j.tetlet.2014.11.121

Cited by 46 publications

(32 citation statements)

References 30 publications

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“…Lipson and co‐workers reported synthesis of the pyrazolo[1,5‐a]pyrimidines derivatives method . Chalcones (3a‐3f) are effective bidentate electrophiles and have been employed for the synthesis of various bioactive heterocyclic.…”

Section: Methodsmentioning

confidence: 99%

Design, synthesis, pharmacological evaluation and DNA interaction studies of binuclear Pt(II) complexes with pyrazolo[1,5‐a]pyrimidine scaffold

Lunagariya

Thakor

Waghela

et al. 2018

Applied Organom Chemis

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Substituted pyrazolo[1,5-a]pyrimidine ligands were synthesized by cyclization, using 3-(thiophen-2-yl)-1H-pyrazol-5-amine with substituted enones (3-phenyl-1-(pyridin-2-yl)prop-2-en-1-one) in presence of KOH and DMF as solvent to form cyclic aromatic compounds. The substituted pyrazolo[1,5-a] pyrimidine based binuclear Pt II complexes containing neutral tetradentated ligands have general formula [Pt 2 (5a-5f)Cl 4 ], (where, (5a -5f) = pyrazolo[1,5-a] pyrimidine ligand). This compounds were characterized by physicochemical and spectroscopic method like elemental analyses, UV-Visible, FT-IR, EDX, TGA, molar conductivity, magnetic susceptibility measurements, mass spectroscopy, 1 H and 13 C NMR method. The square planar geometry was predicted by electronic spectral study. All Pt II compounds were evaluated by antimicrobial assay, in vitro brine shrimp assay, in vivo cellular level bioassay using S. Pombe cells and anti-tuberculosis study. LC 50 (50% lethal concentration) values of compounds are observed between 6.450 -102.07 μg/mL. UV-vis absorption titration, competitive displacement assay, molecular docking and viscosity measurement were carried out to examine the binding type and binding strength of complexes. The binding studies suggest partial intercalative binding mode of the complexes and the observed binding constant (K b ) values are found in the order of 6d > 6b > 6c > 6a > 6e > 6 f. The anti-proliferative cytotoxicity of the synthesized Pt II complexes (6a-6f) were tested against the HCT-116 (Human Colorectal Carcinoma) cancer cell line.

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Section: Methodsmentioning

confidence: 99%

Design, synthesis, pharmacological evaluation and DNA interaction studies of binuclear Pt(II) complexes with pyrazolo[1,5‐a]pyrimidine scaffold

Lunagariya

Thakor

Waghela

et al. 2018

Applied Organom Chemis

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“…Kaswan et al [ 103 ] reported the reaction of 5-aminopyrazoles 16/126 with chalcones 156 in DMF in the presence of inorganic base KOH for the synthesis of 5,7-diarylpyrazolo[1,5- a ]pyrimidines 157 . Chalcones 156 with electron-withdrawing group like nitro, cyano on para- position of aryl or heteroaryl ring and 2-hydroxyphenyl group resulted in lower yields as compared to chalcones with electron-donating groups ( Scheme 44 ).…”

Section: Reviewmentioning

confidence: 99%

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

Aggarwal

Kumar

2018

Beilstein J. Org. Chem.

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The condensation of 5-aminopyrazole with various bielectrophilic moieties results in the formation of pyrazoloazines, an interesting array of fused heterocyclic systems. The development of new synthetic routes towards pyrazoloazines for their biological and medicinal exploration is an attractive area for researchers throughout the world. The present review focuses on various synthetic methods developed in the last decade for the synthesis of differently substituted pyrazoloazines by a broad range of organic reactions by means of 5-aminopyrazole as a precursor. ReviewPyrazole and its derivatives are known to exhibit significant biological and pharmacological activities such as: anticancer [1,2], anti-inflammatory [3,4], antioxidant [5], antibacterial [6][7][8], analgesic [9], antiviral [10,11], antimicrobial [12,13], antifungal [6], antiglycemic [14], antiamoebic [15] and antidepressive [16,17]. Considering the immense biological properties pyrazole is one of the most widely studied nitrogen-containing heterocyclic nuclei. Fused pyrazole derivatives are composed of the pyrazole nucleus attached to other heterocyclic moieties which enable them to exhibit improved pharmacological activities compared to the isolated fragments. These compounds are currently used in several marketed drugs like cartazolate (1), zaleplon (2), sildenafil (3), allopurinol (4), indiplon (5), etazolate (6) etc. (Figure 1). Fused pyrazole derivatives, especially pyrazoloazines have been reported to mimic purine bases, present in DNA and RNA, due to close structural resemblance.In addition to the immense biological potential related to fused pyrazoles, their synthetic potential needs to be reviewed for further improvements and extension of interests. Various efforts have been developed for the synthesis of pyrazole-based fused heterocycles. 5-Aminopyrazoles have been extensively employed as useful synthons in designing and constructing a Beilstein J. Org. Chem. 2018, 14, 203-242. 204 A number of review articles have been published by us and others highlighting the synthetic and biological aspects of 5-aminopyrazoles [26][27][28] as well as on the synthesis of fused pyrazole derivatives [25]. However, a perusal of literature reveals that the importance of 5-aminopyrazoles as synthetic precursors for fused heterocycles has not been reported till now to the best of our knowledge. Recent literature shows resurgence of interest in the chemistry and bioactivity of 5-aminopyrazole derivatives leading to improvements in several already known reactions and syntheses of various fused heterocyclic derivatives with various biological activities. Considering the synthetic importance of 5-aminopyrazoles and synthesis of fused pyrazole derivatives with the need for a more general collection, herein we report an exhaustive overview of the main developments in the last decade in the chemistry of 5-aminopyrazoles for the design and synthesis of fused pyrazoloazines.The typical reactivity of 5-aminopyrazoles 5-Aminopyrazoles are polyfunctional co...

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“…All of these strategies have various drawbacks; the scope of the substrate is restricted, synthesis procedures are long and require several steps, regioselectivity is poor, and harsh reaction conditions are required. Although many methods of synthesis of substituted pyrazolo[1,5‐ a ]pyrimidines are described in the literature, to our knowledge there have been few reports that describe the synthesis of 5,7‐disubstituted pyrazolo[1,5‐ a ]pyrimidines , . New, simple and easy strategies are therefore required to generate a library of new substituted pyrazolo[1,5‐ a ]pyrimidines that can incorporate a number of aspects of structural diversity and a variety of substitution patterns in the target pyrazolo[1,5‐ a ]pyrimidine library, so that the biological properties of this heterocycle system can be investigated further.…”

Section: Introductionmentioning

confidence: 99%

Concise and Efficient Access to 5,7‐Disubstituted Pyrazolo[1,5‐a]pyrimidines by Pd‐Catalyzed Sequential Arylation, Alkynylation and SN_Ar Reaction

et al. 2017

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A simple and efficient method for synthesis of 5,7‐disubstituted pyrazolo[1,5‐a]pyrimidines is reported. The synthetic route involved first a one‐pot two‐step synthesis of 7‐substituted pyrazolo[1,5‐a]pyrimidin‐5‐ones from the reaction of 3‐aminopyrazole 1 with activated alkynes. These compounds were used as key intermediates to access, with excellent yields, a library of new 5,7‐disubstituted pyrazolo[1,5‐a]pyrimidines, which are known for their wide range of biological activities, through C–O bond activation with PyBroP (bromotripyrrolidinophosphonium hexafluorophosphate) as an activator reagent.

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Synthesis of 5,7-diarylpyrazolo[1,5- a ]pyrimidines via KOH mediated tandem reaction of 1 H -pyrazol-3-amines and chalcones

Cited by 46 publications

References 30 publications

Design, synthesis, pharmacological evaluation and DNA interaction studies of binuclear Pt(II) complexes with pyrazolo[1,5‐a]pyrimidine scaffold

Design, synthesis, pharmacological evaluation and DNA interaction studies of binuclear Pt(II) complexes with pyrazolo[1,5‐a]pyrimidine scaffold

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

Concise and Efficient Access to 5,7‐Disubstituted Pyrazolo[1,5‐a]pyrimidines by Pd‐Catalyzed Sequential Arylation, Alkynylation and SN_Ar Reaction

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Synthesis of 5,7-diarylpyrazolo[1,5- a ]pyrimidines via KOH mediated tandem reaction of 1 H -pyrazol-3-amines and chalcones

Cited by 46 publications

References 30 publications

Design, synthesis, pharmacological evaluation and DNA interaction studies of binuclear Pt(II) complexes with pyrazolo[1,5‐a]pyrimidine scaffold

Design, synthesis, pharmacological evaluation and DNA interaction studies of binuclear Pt(II) complexes with pyrazolo[1,5‐a]pyrimidine scaffold

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

Concise and Efficient Access to 5,7‐Disubstituted Pyrazolo[1,5‐a]pyrimidines by Pd‐Catalyzed Sequential Arylation, Alkynylation and SNAr Reaction

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Concise and Efficient Access to 5,7‐Disubstituted Pyrazolo[1,5‐a]pyrimidines by Pd‐Catalyzed Sequential Arylation, Alkynylation and SN_Ar Reaction