A facile one-pot synthesis of 1-arylpyrazolo[3,4-d]pyrimidin-4-ones

Novel Glu-based pyrazolo[3,4-d]pyrimidine analogues: design, synthesis and biological evaluation as DHFR and TS dual inhibitors

A novel series of multifunctional pyrazolo[3,4-d]pyrimidine-based glutamate analogs (6a-l and 7a,b) have been designed and synthesized as antifolate anticancer agents. Among the tested compounds, 6i exhibited the most potent anti-proliferative activity towards NSCLC, CNS, Ovarian, Prostate, Colon, Melanoma, Breast, and Renal cancers with good to weak cytostatic activity and non-lethal actions. 6i demonstrated higher selectivity for cancer than normal cells. 6i could significantly increase the accumulation of S-phase cells during the cell cycle distribution of cancer cells with high potency in the induction of apoptosis. The results unveiled that 6i probably acts through dual inhibition of DHFR and TS enzymes (IC₅₀ = 2.41 and 8.88 µM, correspondingly). Docking studies of 6i displayed that N1-p-bromophenyl and C3-Methyl groups participate in substantial hydrophobic interactions. The drug-likeness features inferred that 6i met the acceptance criteria of Pfizer. Taking together, 6i could be a promising prototype for further optimization as an effective anticancer drug.

Design, Synthesis, and Biological Evaluation of a Novel VEGFR-2 Inhibitor Based on a 1,2,5-Oxadiazole-2-Oxide Scaffold with MAPK Signaling Pathway Inhibition

Over the past few decades, the development of broad-spectrum anticancer agents with anti-angiogenic activity has witnessed considerable progress. In this study, a new series of pyrazolo[3,4-d]pyrimidines based on a phenylfuroxan scaffold were designed, synthesized, and evaluated, in terms of their anticancer activities. NCI-60 cell one-dose screening revealed that compounds 12a-c and 14a had the best MGI%, among the tested compounds. The target fluorinated compound 12b, as the most active one, showed better anticancer activity compared to the reference drug sorafenib, with IC50 values of 11.5, 11.6, and 13 µM against the HepG-2, A2780CP, and MDA-MB-231 cell lines, respectively. Furthermore, compound 12b (IC50 = 0.092 µM) had VEGFR-2-inhibitory activity comparable to that of the standard inhibitor sorafenib (IC50 = 0.049 µM). Furthermore, the ability of compound 12b in modulating MAPK signaling pathways was investigated. It was found to decrease the level of total ERK and its phosphorylated form, as well as leading to the down-regulation of metalloproteinase MMP-9 and the over-expression of p21 and p27, thus leading to subG1 cell-cycle arrest and, thus, the induction of apoptosis. Additionally, compound 12b decreased the rate of wound healing in the absence of serum, in comparison to DMSO-treated cells, providing a significant impact on metastasis inhibition. The quantitative RT-PCR results for E-cadherin and N-cadherin showed lower expression of the neuronal N-cadherin and increased expression of epithelial E-cadherin, indicating the ability of 12b to suppress metastasis. Furthermore, 12b-treated HepG2 cells expressed a low level of anti-apoptotic BCL-2 and over-expressed proapoptotic Bax genes, respectively. Using the DAF-FM DA fluorescence probe, compound 12b produced NO intracellularly as efficiently as the reference drug JS-K. In silico molecular docking studies showed a structural similarity through an overlay of 12b with sorafenib. Interestingly, the drug-likeness properties of compound 12b met the expectations of Pfizer's rule for the design of new drug candidates. Therefore, this study presents a novel anticancer lead compound that is worthy of further investigation and activity improvement.

Recent Developments in the Synthesis of Bicyclic Condensed Pyrimidinones

Abstract:

Functionalized bicyclic pyrimidinones and their derivatives are significant heterocyclic scaffolds being their all-around prevalence in biologically potent compounds. In several attempts to explore the different synthetic methodologies for the construction of bicyclic condensed pyrimidinones, different researchers from all across the globe have reported numerous substantial methods. In the present review, considerable work has been critically compiled on the synthesis of substituted and functionalized bicyclic pyrimidinones from 2000 onwards.

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

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.

Design and synthesis of pyrazolo[3,4-d]pyrimidines: Nitric oxide releasing compounds targeting hepatocellular carcinoma

A new series of pyrazolo[3,4-d]pyrimidines tethered with nitric oxide (NO) producing functionality was designed and synthesized. Sulforhodamine B (SRB) protein assay revealed that NO releasing moiety in the synthesized compounds significantly decreased the cell growth more than the des-NO analogues. Compounds 7C and 7G possessing N-para-substituted phenyl group, released the highest NO concentration of 4.6% and 4.7% respectively. Anti-proliferative activity of synthesized compounds on HepG2 cell line identified compounds 7h, 7p, 14a and 14b as the most cytotoxic compounds in the series of IC₅₀=3, 5, 3 and 5μM, respectively, compared to erlotinib as a reference drug (IC₅₀=25μM). Flow cytometry studies revealed that 7h arrested the cells in G0/G1 phase of cell cycle while 7p arrested the cells in S phase. Moreover, docking study of the synthesized compounds on EGFR (PDB code: 1M17) and cytotoxicity study indicated that N-1 phenyl para substitution, pyrazole C-3 alkyl substitution and tethering the nitrate moiety through butyl group had a significant impact on the activity.

Microwave-assisted synthesis and antibacterial evaluation of new derivatives of 1,2-dihydro-3H-pyrazolo[3,4-d]pyrimidin-3-one

Synthesis of new 1,2-dihydro-3H-pyrazolo[3,4-d] pyrimidin-3-ones4–6starting with ethyl 4-hydroxy-2-methylthio-pyrimidine-5-carboxylate (1) under classical heating and microwave-induced conditions is reported. The antibacterial activities of the synthesized compounds were evaluated using chloramphenicol and streptomycin as reference drugs.

Progress of the synthesis of condensed pyrazole derivatives (from 2010 to mid-2013)

Condensed pyrazole derivatives are important heterocyclic compounds due to their excellent biological activities and have been widely applied in pharmaceutical and agromedical fields. In recent years, numerous condensed pyrazole derivatives have been synthesized and advanced to clinic studies with various biological activities. In this review, we summarized the reported synthesis methods of condensed pyrazole derivatives from 2010 until now. All compounds are divided into three parts according to the rings connected to pyrazole-ring, i.e. [5, 5], [5,F 6], and [5, 7]-condensed pyrazole derivatives. The biological activities and applications in pharmaceutical fields are briefly introduced to offer an orientation for the design and synthesis of condensed pyrazole derivatives with good biological activities.

Design, Synthesis, and Antitumor Evaluation of Novel Pyrazolo[3,4-d]pyrimidine Derivatives

A new series of pyrazolo[3,4-d]pyrimidines has been synthesized. The new compounds were tested for their antitumor activity on 60 different cell lines, and some of the compounds were found to have potent antitumor activity. In particular, 2-hydroxybenzaldehyde [1-(4-chlorophenyl)-3-methyl-1H-pyrazolo-[3,4-d]pyrimidin-4-yl]hydrazone (VIIa) was found to be the most effective among the other derivatives, showing IC50 values of 0.326 to 4.31 μM on 57 different cell lines.

Microwave-assisted, divergent solution-phase synthesis of 1,3,6-trisubstituted pyrazolo[3,4-d]pyrimidines

A concise and highly divergent synthetic route has been developed to rapidly access 1,3,6-trisubstituted pyrazolopyrimidines. The synthesis features a microwave assisted one-pot N1-alkylation/Suzuki-Miyaura reaction as the key step. The sequence of the synthetic scheme can be varied to selectively modify the N1, C3, or C6 position at a late synthetic stage, thereby providing a highly efficient approach to explore the structure-activity relationships of pyrazolopyrimidine derivatives. The scope of these reactions has also been explored.