Recent Advances in Metal-Catalyzed Approaches for the Synthesis of Quinazoline Derivatives

Quinazolines are an important class of heterocyclic compounds that have proven their significance, especially in the field of organic synthesis and medicinal chemistry because of their wide range of biological and pharmacological properties. Thus, numerous synthetic methods have been developed for the synthesis of quinazolines and their derivatives. This review article briefly outlines the new synthetic methods for compounds containing the quinazoline scaffold employing transition metal-catalyzed reactions.

2-Thioxo-3,4-dihydropyrimidine and thiourea endowed with sulfonamide moieties as dual EGFRT790M and VEGFR-2 inhibitors: Design, synthesis, docking, and anticancer evaluations

The effectiveness of a new series of thiopyrimidine and thiourea containing sulfonamides moieties was tested on HCT-116, MCF-7, HepG2, and A549. HepG2 cell line was the one that all the new derivatives affected the most. The greatest potent compounds against the four HepG2, HCT116, MCF-7, and A549 cell lines were 8f and 8g with IC50  = 4.13, 6.64, 5.74, 6.85 µM and 4.09, 4.36, 4.22, 7.25 µM correspondingly. Compound 8g exhibited higher activity than sorafenib against HCT116 and MCF-7 but exhibited lower activity against HepG2 and A549. Moreover, compounds 8f and 8g exhibited higher activities than erlotinib on HepG2, HCT116, and MCF-7 but demonstrated lower activity on A549. The most potent cytotoxic derivatives 6f, 6g, 8c, 8d, 8e, 8f, and 8g were examined on normal VERO cell lines. Our derivatives have low toxicity on VERO cells with IC50 values ranging from 32.05 to 53.15 μM. Additionally, all compounds were assessed for dual VEGFR-2 and EGFRT790M inhibition effects. Compounds 8f and 8g were the most potent derivatives inhibited VEGFR-2 at IC50 value of 0.88 and 0.90 µM, correspondingly. As well, derivatives 8f and 8g could inhibit EGFRT790M demonstrating strongest effects with IC50  = 0.32 and 0.33 µM sequentially. Additionally, the greatest active derivatives ADMET profile was evaluated in relationship with sorafenib and erlotinib as reference agents. The data attained from docking were greatly related to that achieved from the biological testing.

Five and six membered heterocyclic rings endowed with azobenzene as dual EGFRT790M and VEGFR-2 inhibitors: design, synthesis, in silico ADMET profile, molecular docking, dynamic simulation and anticancer evaluations

Novel azobenzene scaffold-joined heterocyclic isoxazole, pyrazole, triazole, and/or triazine moieties have been developed and synthesized utilizing microwave and traditional methods. Our compounds were tested for growth inhibition of A549, MCF-7, HCT-116, and HepG2 tumors by dual targeting the VEGFR-2 and EGFRT790M enzymes. The suggested compound's manner of binding with EGFRT790M and VEGFR-2 active sites was explored through molecular design and MD modeling. The information from the results of the biological screening and the docking studies was highly correlated. The A549 cell line was the one that responded to the novel compound's effects most effectively. Having IC50 values of 5.15, 6.37, 8.44 and 6.23 μM, respectively, 14 was the most effective derivative on the four A549, MCF-7, HCT116 and HepG2 cancer cells. It had greater activity than erlotinib and slightly inferior activities on the tested cell lines than sorafenib, respectively. The cytotoxicity of the most effective derivatives, 5, 6, 10 and 14, was evaluated against typical VERO cell lines. Having IC50 values ranging from 42.32 to 55.20 μM, the results showed that the investigated drugs have modest toxicity against VERO normal cells. Additionally all derivatives were assessed for their dual VEGFR-2 and EGFRT790M inhibitory effects. Among them, derivatives 14, 5 and 10 were established as the greatest inhibitors of VEGFR-2 at IC50 values of 0.95, 1.25 and 1.50 μM correspondingly. As well, derivatives 14, 6, 5 and 10 could inhibit EGFRT790M activity demonstrating strongest effects with IC50 = 0.25, 0.35, 0.40 and 0.50 μM respectively. Furthermore, the ADMET profile was evaluated for compounds 5, 6, 10 and 14 in contrast to reference drugs sorafenib and erlotinib.

Quinazoline-based VEGFR-2 inhibitors as potential anti-angiogenic agents: A contemporary perspective of SAR and molecular docking studies

Angiogenesis, the formation of new blood vessels from the existing vasculature, is pivotal in the migration, growth, and differentiation of endothelial cells in normal physiological conditions. In various types of tumour microenvironments, dysregulated angiogenesis plays a crucial role in supplying oxygen and nutrients to cancerous cells, leading to tumour size growth. VEGFR-2 tyrosine kinase has been extensively studied as a critical regulator of angiogenesis; thus, inhibition of VEGFR-2 has been widely used for cancer treatments in recent years. Quinazoline nucleus is a privileged and versatile scaffold with a broad range of pharmacological activity, especially in the field of tyrosine kinase inhibitors with more than twenty small molecule inhibitors approved by the US Food and Drug Administration in the last two decades. As of now, the U.S. FDA has approved eleven small chemical inhibitors of VEGFR-2 for various types of malignancies, with a prime example being vandetanib, a quinazoline derivative, which is a multi targeted kinase inhibitor used for the treatment of late-stage medullary thyroid cancer. Despite of prosperous discovery and development of VEGFR-2 down regulator drugs, there still exists limitations in clinical efficacy, adverse effects, a high rate of clinical discontinuation and drug resistance. Therefore, there is an urgent need for the design and synthesis of more selective and effective inhibitors to tackle these challenges. Through the gathering of this review, we have strived to broaden the extent of our view over the entire scope of quinazoline-based VEGFR-2 inhibitors. Herein, we give an overview of the importance and advancement status of reported structures, highlighting the SAR, biological evaluations and their binding modes.

Design, synthesis, and docking of novel thiazolidine-2,4-dione multitarget scaffold as new approach for cancer treatment

Novel thiazolidine-2,4-diones have been developed and estimated as conjoint inhibitors of EGFR^T790M and VEGFR-2 against HCT-116, MCF-7, A549, and HepG2 cells. Compounds 6a, 6b, and 6c were known to be the dominant advantageous congeners against HCT116 (IC₅₀  = 15.22, 8.65, and 8.80 µM), A549 (IC₅₀  = 7.10, 6.55, and 8.11 µM), MCF-7 (IC₅₀  = 14.56, 6.65, and 7.09 µM) and HepG2 (IC₅₀  = 11.90, 5.35, and 5.60 µM) mass cell lines, correspondingly. Although compounds 6a, 6b, and 6c disclosed poorer effects than sorafenib (IC₅₀  = 4.00, 4.04, 5.58, and 5.05 µM) against the tested cell sets, congeners 6b and 6c demonstrated higher actions than erlotinib (IC₅₀  = 7.73, 5.49, 8.20, and 13.91 µM) against HCT116, MCF-7 and HepG2 cells, yet lesser performance on A549 cells. The hugely effective derivatives 4e-i and 6a-c were inspected versus VERO normal cell strains. Compounds 6b, 6c, 6a, and 4i were found to be the most effective derivatives, which suppressed VEGFR-2 by IC₅₀  = 0.85, 0.90, 1.50, and 1.80 µM, respectively. Moreover, compounds 6b, 6a, 6c, and 6i could interfere with the EGFR^T790M performing strongest effects with IC₅₀  = 0.30, 0.35, 0.50, and 1.00 µM, respectively. What is more, 6a, 6b, and 6c represented satisfactory in silico computed ADMET profile.

Recent development of multi-target VEGFR-2 inhibitors for the cancer therapy

Vascular epidermal growth factor receptor-2 (VEGFR-2), as an important tyrosine transmembrane protein, plays an important role in regulating endothelial cell proliferation and migration, regulating angiogenesis and other biological functions. VEGFR-2 is aberrantly expressed in many malignant tumors, and it is also related to the occurrence, development, and growth of tumors and drug resistance. Currently, there are nine VEGFR-2 targeted inhibitors approved by US.FDA for clinical use as anticancer drugs. Due to the limited clinical efficacy and potential toxicity of VEGFR inhibitors, it is necessary to develop new strategies to improve the clinical efficacy of VEGFR inhibitors. The development of multitarget therapy, especially dual-target therapy, has become a hot research field of cancer therapy, which may provide an effective strategy with higher therapeutic efficacy, pharmacokinetic advantages and low toxicity. Many groups have reported that the therapeutic effects could be improved by simultaneously inhibiting VEGFR-2 and other targets, such as EGFR, c-Met, BRAF, HDAC, etc. Therefore, VEGFR-2 inhibitors with multi-targeting capabilities have been considered to be promising and effective anticancer agents for cancer therapy. In this work, we reviewed the structure and biological functions of VEGFR-2, and summarized the drug discovery strategies, and inhibitory activities of VEGFR-2 inhibitors with multi-targeting capabilities reported in recent years. This work might provide the reference for the development of VEGFR-2 inhibitors with multi-targeting capabilities as novel anticancer agents.

Exploration of thiazolidine-2,4-diones as tyrosine kinase inhibitors: Design, synthesis, ADMET, docking, and antiproliferative evaluations

As dual EGFR and VEGFR-2 inhibitors, 22 innovative thiazolidine-2,4-diones were modeled, constructed, and measured for their anticancer performance versus four human neoplasms HCT-116, MCF-7, A549, and HepG2. Molecular docking and MD simulation were performed to inspect the binding technique of the proffered congeners with the EGFR and VEGFR-2 receptors. Evidence realized thanks to the docking inquests was vastly consistent together with that detected through the biological screening. Structures 14a and 14g emerged as the most active compounds toward HCT116 (IC₅₀  = 6.01 and 7.44 µM), MCF-7 (IC₅₀  = 5.77 and 7.23 µM), A549 (IC₅₀  = 5.35 and 5.47 µM) and HepG2 (IC₅₀  = 3.55 and 3.85 µM) tumefaction cells. Compounds 14a and 14g exhibited higher events than sorafenib (IC₅₀  = 5.05, 5.58, 4.04, and 4.00 µM) against HepG2 instead subordinate incidents concerning A549, MCF-7, and HCT116, parallelly. Nevertheless, these compounds signified weightier performance than erlotinib (IC₅₀  = 13.91, 8.20, 5.49, 7.73, and µM), with respect to the four cell lines. Compounds having the best activity against the four cell lines, 12a-f, 13a-d, and 14a-g were chosen to appraise their in vitro VEGFR-2 and EGFR^T790M inhibiting activities. The best results were for compounds 14a and 14g compared to sorafenib and erlotinib, respectively, with IC₅₀ values of 0.74 and 0.78 µM and 0.12 and 0.14 µM, respectively. Moreover, 13d, 14a, and 14g showed an adequate in silico calculated ADMET profile. The current investigation presents novel candidates for future optimization to construct mightier and eclectic binary VEGFR-2/EGFR^T790M restrainers with higher antitumor effects.

Nanogel-mediated drug delivery system for anticancer agent: pH stimuli responsive poly(ethylene glycol/acrylic acid) nanogel prepared by gamma irradiation

The popularity of nanogel as nano drug carrier lies in its adjustable physical properties, and the ability to encapsulate drug particles with improved properties is being developed to meet the diverse pH-sensitive nanogel for anticancer agent. Monitoring pH has been identified as an important diagnostic element during the treatment process. A pH-sensitive nanogel consisting of (PEG/PMAc) in the ratio of (50:50%) hasbeen cross-linkedby γ-irradiation techniques at an irradiation dose of 5 kGy. Compound 4 and its nanogel 5 were synthesized and assessed for their anticancer effects against HepG2, A549, MCF-7 and HCT-116 as dual VEGFR-2 and EGFR tyrosine kinases inhibitors. The molecular design was performed to investigate the binding mode of compound 4 with VEGFR-2 and EGFR receptors. Our compound 5 in nanogel showed enhanced anticancer activities against the four tested cancer cell lines and also showed higher inhibition activities against VEGFR-2 and EGFR^T790M kinases than the derivative 4. Finally, our derivative 4 showed good in silico calculated ADMET profile. It was expected to show good GIT absorption in human, lower CNS side effects, no hepatotoxic actions and higher acute and oral chronic toxic doses in comparing to sorafenib and erlotinib. The obtained results showed that, our compound could be useful as a template for future design, optimization, adaptation and investigation to produce more potent and selective dual VEGFR-2/EGFR^T790M inhibitors with higher anticancer activity.

Design, synthesis, in silico docking, ADMET and anticancer evaluations of thiazolidine-2,4-diones bearing heterocyclic rings as dual VEGFR-2/EGFRT790M tyrosine kinase inhibitors

Fourteen recent thiazolidine-2,4-diones bearing furan and/or thiophene heterocyclic rings have been designed, synthesized and assessed for their anticancer activities against four human tumor cell lines HepG2, A549, MCF-7 and HCT-116 targeting both VEGFR-2 and EGFR tyrosine kinases. Molecular design was carried out to investigate the binding mode of the proposed compounds with VEGFR-2 and EGFR receptors. HepG2 was the most susceptible cell line to the influence of our derivatives. Compounds 5g and 4g revealed the highest activities against HepG2 (IC₅₀ = 3.86 and 6.22 μM), A549 (IC₅₀ = 7.55 and 12.92 μM), MCF-7 (IC₅₀ = 10.65 and 10.66 μM) and HCT116 (IC₅₀ = 9.04 and 11.17 μM) tumor cell lines. Sorafenib (IC₅₀ = 4.00, 4.04, 5.58 and 5.05 μM) and elotinib (IC₅₀ = 7.73, 5.49, 8.20 and 13.91 μM) were used as reference standards. Furthermore, the most active cytotoxic compounds 4d, 4e, 4f, 4g, 5d, 5e, 5f and 5g were selected to assess their VEGFR-2 inhibitory effects. Derivatives 5g, 4g and 4f were observed to be the highest effective derivatives that inhibited VEGFR-2 at the submicromolar level (IC₅₀ = 0.080, 0.083 and 0.095 μM respectively) in comparison to sorafenib (IC₅₀ = 0.084 μM). As well, compounds 4d, 4e, 4f, 4g, 5d, 5e, 5f and 5g were additionally assessed for their inhibitory activities against mutant EGFR^T790M. Compounds 5g and 4g could interfere with the EGFR^T790M activity exhibiting stronger activities than elotinib with IC₅₀ = 0.14 and 0.23 μM respectively. Finally, our derivatives 4g, 5f and 5g showed a good in silico calculated ADMET profile. The obtained results showed that our compounds could be useful as a template for future design, optimization, adaptation and investigation to produce more potent and selective dual VEGFR-2/EGFR^T790M inhibitors with higher anticancer activity.

Dual target inhibitors based on EGFR: Promising anticancer agents for the treatment of cancers (2017-)

The EGFR family play a significant role in cell signal transduction and their overexpression is implicated in the pathogenesis of numerous human solid cancers. Inhibition of the EGFR-mediated signaling pathways by EGFR inhibitors is a widely used strategy for the treatment of cancers. In most cases, the EGFR inhibitors used in clinic were only effective when the cancer cells harbored specific activating EGFR mutations which appeared to preserve the ligand-dependency of receptor activation but altered the pattern of downstream signaling pathways. Moreover, cancer is a kind of multifactorial disease, and therefore manipulating a single target may result in treatment failure. Although drug combinations for the treatment of cancers proved to be successful, the use of two or more drugs concurrently still was a challenge in clinical therapy owing to various dose-limiting toxicities and drug-drug interactions caused by pharmacokinetic profiles changed. Therefore, a single drug targeting two or multiple targets could serve as an effective strategy for the treatment of cancers. In recent, drugs with diverse pharmacological effects have been shown to be more advantageous than combination therapies due to their lower incidences of side effects and more resilient therapies. Accordingly, dual target-single-agent strategy has become a popular field for cancer treatment, and researchers became more and more interest in the development of novel dual-target drugs in recent years. In this review, we briefly introduce the EGFR family proteins and synergisms between EGFR and other anticancer targets, and summarizes the development of potential dual target inhibitors based on wild-type and/or mutant EGFR for the treatment of solid cancers in the past five years. Additionally, the rational design and SARs of these dual target agents are also presented in detailed, which will lay a significant foundation for the further development of novel EGFR-based dual inhibitors with excellent druggability.

Novel 4-Anilinoquinazoline Derivatives as Potent Anticancer Agents: Design, Synthesis, Cytotoxic Activity, and Docking Study

The simultaneous inhibition of EGFR and VEGFR-2 is a promising method in cancer treatment. In the present work, several 4-anilinoquinazoline derivatives encompassing different substitutions at the C-4 and C-7 positions of a quinazoline core were designed, synthesised, and evaluated for their cytotoxicity on A431, HUVEC, and HU02 cell lines. Docking studies were carried out to test the interactions of all synthesised compounds with EGFR and VEGFR-2. Furthermore, a wound healing assay was done for the investigation of cell migration. The most potent compound was 8l followed by the compounds 8i and 8j which showed better cytotoxic activities on A431 and HUVEC cell lines than the standard (Vandetanib). The compounds 8f and 8a represented the best docking energies of 8.99 and 9.35 kcal mol−1 for EGFR and VEGFR, respectively. Moreover, molecular docking studies exhibited that compound 8l showed efficient binding affinity against both EGFR and VEGFR-2. It can bind to these receptors through the formation of essential hydrogen bonds between the quinazoline N1 atom and the Met796 backbone of EGFR and two hydrogen bonds with Cys919 and Thr916 of VEGFR-2 with energies of –7.99 and –7.85 kcal mol−1, respectively. In addition, this compound displayed the highest activity on cell migration and wound healing. Compound 8l with the highest cytotoxic activity can be considered a candidate for further investigation and structural optimisation as an antiproliferative agent.

6,7-Disubstituted-4-anilinoquinazoline: Design, Synthesis and Anticancer Activity as a Novel Series of Potent Anticancer Agents

Background: Epidermal Growth Factor Receptor (EGFR) and vascular endothelial growth factor receptor (VEGFR) are responsible for several pathological conditions such as the development of different kinds of tumors. The combined inhibition of both signal transduction pathways seems to be a promising novel approach for cancer treatment. Methods: In this study, novel 4-anilinoquinazoline derivatives with various substituents on-7 position of quinazoline moiety were designed, synthesized, and evaluated for their antiproliferative activity against A431 and HU02 cell lines. Results: Compounds 8a, 8d, and 8f displayed the most potent anticancer activities against A431(IC50 = 1.78 μM, 8.25 μM, and 7.18 μM, respectively) in comparison with reference standards(erlotinib IC50=8.31 μM and vandetanib IC50=10.62 μM). Molecular docking studies proved that8a as the most potent compound could be efficiently accommodated in the ATP binding site ofEGFR and VEGFR-2 through the formation of essential hydrogen bonds between quinazolineN1 atom and the Met796 backbone of EGFR as well as the Cys919 backbone of VEGFR-2 with a distance of 1.94 Å and 1.398 Å, respectively. Conclusion: Compound 8a as the most potent compound with morpholine and 3-bromoaniline at the 7 and 4 positions of quinazoline scaffold, respectively, deserves more study and structural optimization as an anticancer agent.

Novel thienopyrimidine derivatives as dual EGFR and VEGFR-2 inhibitors: design, synthesis, anticancer activity and effect on cell cycle profile

Aim: Design and synthesis of thienopyrimidine derivatives as dual EGFR and VEGFR-2 inhibitors.Material and methods: A series of novel 6,7,8,9-tetrahydro-5H-cyclohepta[4,5]thieno[2,3-d]pyrimidine derivatives with different substituents on C-4 position was synthesized and evaluated for their anticancer activity against MCF-7 cell line. EGFR, VEGFR-2 inhibitory assay, the cell cycle analysis and apoptosis induction ability of the most potent compound 5f were evaluated.Results: Most of the compounds showed moderate to significant anticancer activity. Compound 5f exhibited the most potent anticancer activity being 1.73- and 4.64-folds more potent than erlotinib and doxorubicin, respectively. Compound 5f showed potent EGFR inhibitory activity being 1.18-folds more potent than reference standard erlotinib and it also showed good VEGFR-2 inhibitory activity at the micromolar level with IC₅₀ value 1.23 µM. Compound 5f caused induction of cell cycle arrest at G2/M phase and accumulation of cells in pre-G1 phase. Compound 5f induced cellular apoptosis.

PI3K Inhibitors of Novel Hydrazide Analogues Linked 2-Pyridinyl Quinazolone Scaffold as Anticancer Agents

A series of novel 2-(pyridin-4-yl)quinazolin-4(3H)-ones bearing different heterocycle cores as potential PI3K inhibitors have been synthesized and evaluated via the MTT assay for their antiproliferative properties against selected HePG-2, MCF-7, and HCT116 cancer cell lines. Among them, compound 9 displayed significant activity against HePG-2 (IC50 = 60.29 ± 1.06 μM) comparable to doxorubicin as a reference anticancer drug (IC50 = 69.60 ± 1.50 μM). Kinase inhibitory assessment of target products against PI3K and docking studies revealed the promising binding affinities which match with the binding mode of the ligand, SW13 towards the active site of PI3K. Therefore, this work represents a promising matrix for developing novel potential anticancer candidates.

A one-pot synthetic approach for the construction of a thiazolo[3,2-a]benzimidazole-linked quinazoline scaffoldviapalladium-catalyzed reactions

4-(2-Substituted-[1,3]thiazolo[3,2-a]benzimidazol-3-yl)quinazolin-2-amines were prepared by the reaction of 2,4-dichloroquinazoline, terminal alkynes, secondary amines, and 1H-benzo[d]imidazole-2(3H)-thione in the presence of palladium catalyst.

Design and Discovery of Quinazoline- and Thiourea-Containing Sorafenib Analogs as EGFR and VEGFR-2 Dual TK Inhibitors

Both EGFR and VEGFR-2 play a critical role in tumor growth, angiogenesis and metastasis, and targeting EGFR and VEGFR-2 simultaneously represents a promising approach to cancer treatment. In this work, a series of novel quinazoline- and thiourea-containing sorafenib analogs (10a–v) were designed and synthesized as EGFR and VEGFR-2 dual TK inhibitors. Their in vitro enzymatic inhibitory activities against EGFR and VEGFR-2, and antiproliferative activities against HCT-116, MCF-7 and B16 cell lines were evaluated and described. Most of the compounds showed potent activities against both cell lines and TK kinases. Compounds 10b and 10q which exhibited the most potent inhibitory activities against EGFR (IC₅₀ = 0.02 µM and 0.01 µM, respectively), VEGFR-2 (IC₅₀ = 0.05 µM and 0.08 µM, respectively), and good antiproliferative activities, also displayed competitive anti-tumor activities than sorafenib in vivo by B16 melanoma xenograft model test.

Quinazolines and quinazolinones as ubiquitous structural fragments in medicinal chemistry: An update on the development of synthetic methods and pharmacological diversification

Nitrogen-rich heterocycles, particularly quinazolines and quinazolinones, represent a unique class of diversified frameworks displaying a broad spectrum of biological functions. Over the past several years, intensive medicinal chemistry efforts have generated numerous structurally functionalized quinazoline and quinazolinone derivatives. Interest in expanding the biological effects, demonstrated by these motifs, is growing exponentially, as indicated by the large number of publications reporting the easy accessibility of these skeletons in addition to the diverse nature of synthetic as well as biological applications. Therefore, the main focus of the present review is to provide an ample but condensed overview on various synthetic approaches providing access to quinazoline and quinazolinone compounds with multifaceted biological activities. Furthermore, mechanistic insights, synthetic utilization, structure-activity relationships and molecular modeling inputs for the potent derivatives have also been discussed.

Novel Quinazoline Derivatives Bearing Various 4-Aniline Moieties as Potent EGFR Inhibitors with Enhanced Activity Against NSCLC Cell Lines

A class of novel quinazoline derivatives bearing various C-4 aniline moieties was synthesized and biologically evaluated as potent epidermal growth factor receptor (EGFR) inhibitors for intervention of non-small-cell lung cancer (NSCLC). Most of these inhibitors are comparable to gefitinib in inhibiting these cancer cell lines, and several of them even displayed superior inhibitory activity. In particular, analogue 5b with an IC50 of 0.10 μm against the EGFR wild-type A431 cells and 5c with an IC50 of 0.001 μm against the gefitinib-sensitive HCC827 cells (EGFR del E746-A750) was identified as highly active EGFR inhibitors. It was also significant that the discovered analogue 2f, not only has high potency against the gefitinib-sensitive cells (IC50 = 0.031 μm), but also possesses remarkably improved activity against the gefitinib-resistant cells. In addition, the enzymatic assays and the Western blot analysis for evaluating the effects of the typical inhibitors indicated that these molecules strongly interfere with the EGFR target.

Design and discovery of 4-anilinoquinazoline-acylamino derivatives as EGFR and VEGFR-2 dual TK inhibitors

Both EGFR and VEGFR-2 are important targets for cancer therapy, the combined inhibition of both EGFR and VEGFR-2 signaling pathway represents a promising approach to the treatment of cancers with a synergistic effect. In this study, a series of novel 4-anilinoquinazoline-acylamino derivatives designed as EGFR and VEGFR-2 dual inhibitors were synthesized and evaluated for biological activities. Most of them exhibited interesting inhibitory potencies against EGFR and VEGFR-2 as well as good antiproliferative activities. Compounds 15a, 15b and 15e exhibited the most potent inhibitory activity against EGFR (IC50 = 0.13 μM, 0.15 μM and 0.69 μM, respectively) and VEGFR-2 (IC50 = 0.56 μM, 1.81 μM and 0.87 μM, respectively), among them, compound 15b showed the highest antiproliferative activities against three cancer cell lines (HT-29, MCF-7 and H460) with IC50 of 5.27 μM, 4.41 μM and 11.95 μM, respectively. Molecular docking established the interaction of 15a with the DFG-out conformation of VEGFR-2, suggesting that they might be type II kinase inhibitors.

Synthetic approaches, functionalization and therapeutic potential of quinazoline and quinazolinone skeletons: the advances continue

The presence of N-heterocycles as an essential structural motif in a variety of biologically active substances has stimulated the development of new strategies and technologies for their synthesis. Among the various N-heterocyclic scaffolds, quinazolines and quinazolinones form a privileged class of compounds with their diverse spectrum of therapeutic potential. The easy generation of complex molecular diversity through broadly applicable, cost-effective, practical and sustainable synthetic methods in a straightforward fashion along with the importance of these motifs in medicinal chemistry, received significant attention from researchers engaged in drug design and heterocyclic methodology development. In this perspective, the current review article is an effort to recapitulate recent developments in the eco-friendly and green procedures for the construction of highly challenging and potentially bioactive quinazoline and quinazolinone compounds in order to help medicinal chemists in designing and synthesizing novel and potent compounds for the treatment of different disorders. The key mechanistic insights for the synthesis of these heterocycles along with potential applications and manipulations of the products have also been conferred. This article also aims to highlight the promising future directions for the easy access to these frameworks in addition to the identification of more potent and specific products for numerous biological targets.

Synthesis and in vitro antitumor evaluation of primary amine substituted quinazoline linked benzimidazole

By combining the structural features of quinazoline and benzimidazole, new hybrid regioisomeric molecules with substituted primary amines have been synthesized. Evaluation of these molecules over 60 cancer cell line panel has identified three molecules as most potent anticancer agents. Compound 10 showed ten and eleven folds more activity than respective quinazoline and benzimidazole class of compounds with GI50 value of 1.64 μM. Compound 11 (GI50 value of 0.81 μM) showed almost twenty and twenty-two fold more activity than quinazoline and benzimidazole analogue, respectively while compound 12 (GI50 value of 4.52 μM) has four fold more activity than quinazoline and benzimidazole analogue. In vitro evaluation of compound 11 exhibited remarkable anticancer activity towards colon cancer cell lines and prostate cancer cell lines at five dose concentrations with GI50 values of 0.34 and 0.31 μM, respectively.

Novel 2-chloro-4-anilino-quinazoline derivatives as EGFR and VEGFR-2 dual inhibitors

Novel 2-chloro-4-anilino-quinazolines designed as EGFR and VEGFR-2 dual inhibitors were synthesized and evaluated for inhibitory effects. EGFR and VEGFR-2 are validated targets in cancer therapy and combined inhibition might be synergistic for both antitumor activity and resistance prevention. The biological data obtained proved the potential of 2-chloro-4-anilino-quinazoline derivatives as EGFR and VEGFR-2 dual inhibitors, highlighting compound 8o, which was approximately 7-fold more potent on VEGFR-2 and approximately 11-fold more potent on EGFR compared to the prototype 7. SAR and docking studies allowed the identification of pharmacophoric groups for both kinases and demonstrated the importance of a hydrogen bond donor at the para position of the aniline moiety for interaction with conserved Glu and Asp amino acids in EGFR and VEGFR-2 binding sites.

Synthesis, antitumor evaluation and docking study of novel 4-anilinoquinazoline derivatives as potential epidermal growth factor receptor (EGFR) inhibitors

Strike a pose! A series of 4-anilinoquinazolines were designed, synthesized and evaluated in vitro against lung and breast cancer cell lines. Several compounds were found to be endowed with cytotoxicity in the low micromolar range. Molecular docking suggests that these compounds bind to EGFR in a similar manner to known EGFR inhibitors.

Synthesis, single crystal and antitumor activities of benzimidazole-quinazoline hybrids

A series of novel regioisomeric hybrids of quinazoline/benzimidazole viz. (3-allyl-2-methyl-3H-benzimidazol-5-yl)-(2-substituted-quinazolin-4-yl)-amine and (1-allyl-2-methyl-1H-benzimidazol-5-yl)-(2-substituted-quinazolin-4-yl)-amine of biological interest were synthesized. All the synthesized compounds were well characterized by (1)H and (13)C NMR as well as mass spectroscopy. The newly synthesized compounds were screened for in vitro antitumor activities against 60 tumor cell lines panel assay. A significant inhibition for cancer cells were observed with compound 9 and also more active against known drug 5-fluorouracil (5-FU) in some tumor cell lines. Compound 9 displayed appreciable anticancer activity against leukemia, colon, melanoma, renal and breast cancer cell lines.

Synthesis and structure-activity relationships of (aryloxy)quinazoline ureas as novel, potent, and selective vascular endothelial growth factor receptor-2 inhibitors

In our continuing search for medicinal agents to treat proliferative diseases, quinazoline derivatives were synthesized and evaluated pharmacologically as epithelial growth factor receptor and vascular endothelial growth factor receptor 2 (VEGFR-2) tyrosine kinase inhibitors. A quantitative structure-activity relationship analysis was conducted to rationalize the structure-activity relationship and to predict how similar the inhibitor-binding profiles of two protein kinases are likely to be on the basis of the docking of lead coumpounds into the ATP-binding site. This model was used to direct the synthesis of new compounds. A series of N-(aromatic)-N'-{4-[(6,7-dimethoxyquinazolin-4-yl)oxy]phenyl}urea were identified as potent and selective inhibitors of the tyrosine kinase activity of VEGFR-2 (fetal liver kinase 1, kinase insert domain-containing receptor). An efficient route was developed that enabled the synthesis of a wide variety of analogues with substitution on several positions of the template. Substitution of diarylurea, competitive with ATP, afforded several analogues with low nanomolar inhibition of enzymatic activity of VEGFR-2. In this paper, we describe the synthesis, structure-activity relationships, and pharmacological characterization of the series.