Synthesis,anticancer evaluation,and molecular modeling study of new 2-(phenylamino)pyrazolo[1,5-a]pyrimidine analogues

The reaction of 3-amino-5-phenylaminopyrazoles 2 with 3-(dimethylamino) acrylonitrile derivatives resulted in a series of substituted pyrazolopyrimidine analogues 4 and 6. The DFT studies of the isolated compounds showed that the frontier molecular orbitals energy gap was close and in the 2.65–2.81 eV range where the derivative 6b has the lowest and both of 4a and 4c have the highest values. Meanwhile, the anticancer activity of the newly synthesized pyrazolopyrimidine analogues have been tested against several different cell lines (MCF-7, PC3, Hep-2 and WI38). The investigated pyrazolopyrimidines showed remarkable cytotoxicity activity against the MCF-7 and Hep-2 cell lines. In comparison to the effects of 5-fluorouracil, IC₅₀ = 10.19 ± 0.42 and 7.19 ± 0.47, compounds 6a-c demonstrated potential anticancer activity with IC₅₀ values for MCF-7 (10.80 ± 0.36–19.84 ± 0.49 μM) and Hep-2 (8.85 ± 0.24–12.76 ± 0.16 μM). Important details regarding the protein's binding sites were disclosed when the produced analogues docked with the crystal structure of the KDM5A protein, which was located in the protein data library.     

Quinoxalines and related compounds—XI: The formation of fused pyrroles by the condensation of haloazines with methylazines

2-Chloroquinoxaline reacts with a series of 2-methyl-3-substituted quinoxalines (1a-j) giving, in moderate yields, 6-substituted-pyrrolo[1,2-a: 4,5-b']-diquinoxalines (2a-j). Similar polycyclic compounds (9a-c; 11b,c; and 13b) are formed from 4-methylquinazolines (8a-c), 1-methylphthalazines (10b,c) and 2-hydroxy-4-methylpyrimidine (12b); the reaction failing with 2-methylquinazolines and 3-methylcinnolines. Polycyclic materials (17a-c) are also obtained by using chloropyrazines (15a,b) as the haloazine component. Four novel ring systems have thus been obtained; the mechanism is discussed.     

Synthesis of functionalized aminopyrazole and pyrazolopyrimidine derivatives: Molecular modeling and docking as anticancer agents

Three new functionalized 4-aminopyrazole derivatives were synthesized and cyclized with phenyl isothiocyanate to yield the corresponding three pyrazolo[4,3-d]pyrimidine analogues. The DFT quantum chemical calculations were utilized in the determination of the frontier molecular orbital energies and Fukui’s indices. The data showed that they have a low HOMO-LUMO energy gap, ranging from 1.16 to 2.35 eV for 5 and 6, respectively. The newly created analogues' cytotoxic qualities were evaluated in comparison to the reference 5-florouracil (5-Fu) using an in vitro MTT cytotoxicity screening investigation toward four different cell lines, including HCT-116, HepG2, MCF-7, and WI38. The results showed variable potency against human cell lines, with MCF-7 and HepG-2 showing cytotoxic selectivity. The most potent agent against MCF-7 and HCT-116 human cancer cells were found to be aminopyrazole and pyrazolopyrimidine derivatives 4–9. The structure–activity relationships (SAR) for the synthesized compounds were discussed. The examined compounds had superior cytotoxic properties; the most potent derivative 7, had an IC₅₀ ranged from 11.51 ± 0.35 to 21.25 ± 0.37 µM. Meanwhile, quantum chemical computation used independent variables E_H, E_L, ΔE_H-L, χ and η were applied to determine the best way to describe activity. As a result, an increase in the HOMO-LUMO gap and hardness will result in an increase in the anticancer activity. While the E_H, E_L, and showed negative coefficients, increasing them will decrease the anticancer activity. Furthermore, 5IVE protein's crystal structure for KDM5A was docked with the newly created aminopyrazole and pyrazolopyrimidine derivatives to afford the theoretical prediction on the KDM5A enzyme.     

Synthesis,antimicrobial and anticancer activities of some new N-methylsulphonyl and N-benzenesulphonyl-3-indolyl heterocycles: 1st Cancer Update

A series of 1-(N-methyl 2a–c and N-benzenesulphonyl-1H-indol-3-yl)-3-aryl-prop-2-ene-1-ones 3a–c were prepared and allowed to react with urea, thiourea or guanidine and gave the pyrimidine derivatives 4a–c to 9a–c. Base catalyzed reaction of 2a–c or 3a–c with ethyl acetoacetate gave cyclohexanone derivatives 10a–c and 11a–c, respectively. Reaction of the latter compounds with hydrazine hydrate afforded indazole derivatives 12a–c and 13a–c, respectively. On the other hand, condensation of 2c or 3c with some hydrazine derivatives namely, hydrazine hydrate, acetyl hydrazine, phenyl hydrazine and benzyl hydrazine hydrochloride gave pyrazole derivatives 14a,b-17a,b, respectively. Moreover, reaction of 2c or 3c with hydroxyl amine hydrochloride gave isoxazole derivatives 18a,b. The newly synthesized compounds were tested for their antimicrobial activity and showed that, compounds 14a, 14b, 15a and 15b were found to be the most active ones of all the tested compounds toward Salmonella typhimurium (ATCC 14,028) compared to the reference drug chloramphenicol. Eighteen new compounds namely, pyrimidin-2(1H)-ones 4a–c and 5a–c, pyrimidin-2(1H)-thiones 6a–c and 7a–c and pyrimidin-2-amines 8a–c and 9a–c were tested for their in vitro cytotoxicity against human liver carcinoma (HEPG2), human breast cancer (MCF7) and human colon cancer (HCT-116) cell lines and showed that, compounds 4c, 5c, 6c, 8c and 9c were found to be the highly active compounds compared to the reference drug doxorubicin.     

Synthesis,characterization, anticancer activity,and molecular docking of some new sugar hydrazone and arylidene derivatives

New sugar hydrazone moieties, their oxadiazoline derivatives, and arylidene analogues were prepared and chemically elucidated using spectroscopic analysis, such as nuclear magnetic resonance, for hydrogen ¹HNMR, carbon ¹³CNMR, elemental analysis, and Infrared (IR). The prepared compounds were purified and tested against breast cancer cells (MCF-7). Compounds 4c, 4d, 6b, and 6d exhibited moderate to very high anti-breast cancer activity, with a percentage of inhibition of 96.19%, 93.08%, 74.33%, and 86.05% respectively; the reference 5-fluorouracil had an inhibitory percentage of 96.02%.     

Synthesis, cytotoxicity and calcium antagonist activity of novel imidazolyl derivatives of 1,8-acridinediones

A series of novel imidazolyl derivatives of fully and partially hydrogenated 1,8-acridinediones were synthesized and assessed for their cytotoxic activity on four different human cancer cell lines (HeLa, MCF-7, LS-180, and Raji cells). Although being inactive on LS-180 and Raji cell lines, the compounds showed weak to moderate anti-tumor activities on other cell lines and their IC₅₀ ranged from 31.7 to more than 100 ??M. Among the synthesized compounds 12b, 13b, 12c and 13c, bearing an electronattracting substituent on the imidazole ring, and 12f and 13f, with a benzyl substituent, showed higher activities. Furthermore, the calcium channel antagonist activity of the derivatives, an undesired effect when these compounds are used as anti-tumor agents, was much lower than that of Nifedipine, a reference antagonist. Imidazolyl derivatives of 1,8-acridinedione represent an interesting template, showing promising biological properties. Further investigation on this chemical scaffold could potentially lead to the discovery of cytotoxic agents with low calcium channel blocking activity.     

Design and synthesis of some novel pyridothienopyrimidine derivatives and their biological evaluation as antimicrobial and anticancer agents targeting EGFR enzyme

A new series of pyridothienopyrimidine derivatives was designed and evaluated as antimicrobial and anticancer agents. The target compounds were synthesized starting with 3-aminothieno[2,3-b]pyridine-2-carboxamide derivative 1 which underwent cyclocondensation reaction with aromatic aldehydes to give the key intermediates 2a,b. By further treatment of 2a,b with various reagents, the target 2,4-disubstituted-pyrido[3′,2′:4,5]thieno[2,3-d]pyrimidines 3a,b–11a,b were obtained. To evaluate the antimicrobial activity of the new compounds, they were tested against five bacterial and five fungal strains. Compounds 6c, 8b, 9a and 9b revealed the most significant antimicrobial activity against the tested microorganisms with MIC values range (4–16 μg/mL). Also, compounds 2a,b–11a,b were screened for their in vitro cytotoxic activity against HepG-2 and MCF-7 cancer cell lines compared with doxorubicin and cisplatin as references drugs. Moreover, compounds (2b, 4a, 6a, 7b, 7c and 9a) which exhibited the most potent anticancer activity, were further subjected to EGFR^WT enzyme inhibition assay utilizing erlotinib as a standard drug. The compounds 6a, 7b, 7c and 9a which showed the most promising suppression effects were also evaluated as inhibitors against the mutant forms EGFR^L858R and EGFR^T790M. The 4-aminopyrazolone analogue 9a showed superior anticancer activity against both HepG-2 and MCF-7 cell lines (IC50 = 1.27, 10.80 μM, respectively) and more potent enzymatic inhibition activity against EGFR^WT and its mutant forms EGFR^L858R and EGFR^T790M than that obtained by erlotinib (IC₅₀ = 0.021, 0.053, 0.081 µM, respectively, IC_50erlotinib; 0.027, 0.069, 0.550 µM, respectively). Finally, the molecular docking study showed good binding patterns of the most active compounds with the prospective target EGFR^WT.     

Nucleophilic substitution of α-halo-ketones. XXIII. Acetolysis of 1-chloro-3-phenoxy-1-phenylthio-2-propanones. An intramolecular trans-acetylation involving phenoxide anion as the leaving group

The acetolyses of α-chloro-ketones1a-c,2a-c,9a and11a have been investigated parallely. Several aspects of the mechanisms involved in chlorine normal and cine substitution have been elucidated. Intramolecular trans-acetylation, ultimately leading to fragmentation of acetoxy-ketones3b,4a and4c, have been postulated to account for the formation of thiol ester6, aldehyde5a and ketone5c, respectively.     

Zur Kenntnis der Struktur der Chalkon-Guanidin-Kondensate Über Heterocyclen, 75. Mitt.

Guanidine reacts with chalkone1 a, 4-methylchalkone1 b and 4′-methylchalkone1 c resp. to yield mixtures of pyrimidinamines2 a,3 b and3 c (=3 b) resp. with (2:1)-condensatesA,B andC resp. The structures of the compoundsA-C (whicha priori could be dihydropyrimidopyrimidines4 a-c or5 a-c or6 a-c) are elucidated. NMR-investigations show that the saltsA-C · HCl must be symmetrically substituted pyrimidopyrimidinyliumchlorides4 a-c · HCl or5 a-c · HCl (and not6 a-c · HCl). Furthermore, it is proved by chemical methods that the condensatesB · HCl andC · HCl are pyrimidopyrimidinyliumchlorides4 b andc · HCl (and not5 b andc · HCl): The structure ofB · HCl (=4 b · HCl) was established by total synthesis of dimethylpyrimidopyrimidinyliumpicrate9 b-Pi from10 c (via13 c · HI-18 · HCl) and transformation ofB · HCl into an identical salt9 b-Pi via hexahydropyrimidopyrimidine8 b · HCl. The structure ofC · HCl (=4 c · HCl) was determined by comparison of its hydrogenation product (=8c · HCl) with8 b · HCl. The structure of condensateA · HCl (=4 a · HCl) results from conclusion by analogy. The spatial structure of4 a-c · HCl and8 a-c · HCl is discussed; it was established by NMR that the salts are racemic mixtures of stereoisomers4 a-c K · HCl and8 a-c K · HCl resp. and their antipodes (with C₂ symmetry).     

One-pot multicomponent synthesis of novel 1-thiazolyl-5-coumarin-3-yl-pyrazole derivatives and evaluation of their cytotoxic activity

A series of novel 1-thiazolyl-5-coumarin-3-yl-pyrazole derivatives (4a–l) were synthesized via one-pot multicomponent reaction of 5-substituted salicylaldehydes (1a–c), 4-hydroxy-6-methyl-2H-pyran-2-one (2) and 2-hydrazinyl-4-arylthiazoles (3a–d) in acetonitrile using a catalytic amount of piperidine under reflux conditions. This multicomponent approach has advantages such as reduced reaction time and a high product yield percentage when compared with corresponding multistep approaches. All the synthesized compounds were evaluated for their cytotoxic activity against Hep G2 (hepatocellular liver carcinoma) and MCF-7 (breast cancer) cell lines and compared with the standard drug Doxorubicin. Among all the compounds, compounds 4d against Hep G2, 4k against MCF-7 and 4e against both Hep G2 & MCF-7 showed excellent cytotoxic activity.     

Hydantoins,thiohydantoins, glycocyamidines—36: 1,5,5- and 3,5,5-triphenyl derivatives

In contrast to the α-chloroamides 1a-c which, when reacted with potassium N-cyanoanilide, furnish anomalous substitution products (2a-c), the related nitrile and ester yields normal substitution products (3a and b) under the same conditions. 1,5,5-Triphenylhydantoin (4a) and a series (5a-8a, 13 and 14) of its derivatives have been prepared starting with 3a and b. Acid hydrolysis of 3a yields, in addition to the normal products (4a and 5a) considerable quantities of the rearranged product 4b. An authentic sample of the latter, as well as a series of its derivatives (5b-8b and 11) have been prepared starting with α,α-diphenylglycinonitrile and 2-methylthio-1,4,4-triphenyl-2-imidazolin-5-one (9). When reacted with ammonia and ammonium iodide, 9 gave, in addition to the normal ammonolysis product 7b, the Dimroth rearrangement product 16, as well as 5,5-diphenylglycocyamidine, by apparent dephenylation of 16. The mass spectra of the imidazole derivatives 4–8, a and b, 9, 11, 13 and 14 are discussed.     

Siliciumorganische verbindungen: LXXXIV. Silylierte cyclobutene

By Photoaddition of maleic anhydride to the trimethylsilysubstituted acetylenes (1a-c the trimethylsilylated cyclobut-3-ene-1,2-dicarboxylic acid anhydrides (2a-c are obtained. Hydrolysis of 2a-c leads to the cis-dicarboxylic acids (3a-c, which are esterified with diazomethane to give the dimethyl esters (4a-c. 2a-c are reduced to the silylated 3,4-bis(hydroxymethyl)-cyclobut-1-enes (5a-c. The bicyclic compounds 6a, 7a und b are obtained by the etherification of 5a-c.     

Synthesis and in vitro cytotoxic evaluation of some novel hexahydroquinoline derivatives containing benzofuran moiety

A series of new ethyl 4-(2-(benzofuran-2-yl)-4-substituted-1,4,5,6,7,8-hexahydroquinolin-1-yl)-benzoate 3a–c was synthesized by Michael condensation of benzofuran chalcones 1a–c and cyclohexanone to give 2-(2-benzofuranyl)-4-substituted-5,6,7,8-tetrahydro-4-H -chromene 2a–c, followed by reaction of the latter with ethyl 4-aminobenzoate. Condensation of 3a–c with different amines afforded the corresponding amides 4a–e. On the other hand, upon treatment compounds 3a–c with hydrazine hydrate gave the benzohydrazide derivatives 5a–c. The reaction of compounds 5a–c with different thio/isocyanate gave the corresponding thiosemicarbazide and semicarbazide derivatives 6a–c. Meanwhile compounds 5a–c were reacted with ethyl cyanoacetate and different β-dicarbonyl compounds such as acetyl acetone, ethyl acetoacetate, and diethyl malonate to afford pyrazolyl derivatives 7a, b; 8a, b; 9a, b; and 10a–c, respectively. Moreover, 5a–c were reacted with carbon disulfide to synthesize the corresponding oxadiazolyl derivatives 11a–c, while their condensation with different aromatic aldehydes gave the corresponding Schiff bases 12a–d. Cytotoxic evaluation of some of the newly synthesized compounds against human hepatocellular carcinoma cell lines (HepG-2) revealed that the tested compounds produce promising inhibitory effect against the growth of HepG-2 cells with IC₅₀ values ranged from 11.9 to 19.3 µg/mL.     

Synthesis and biological evaluation of novel triazole substituted pyrazolyl-methylenehydrazinyl-5-arylidene thiazolidinone derivatives as antibacterial and cytotoxic agents

Novel triazole substituted pyrazolyl-methylenehydrazinyl-5-arylidene thiazolidinone derivatives 6a–n and 7a–l were synthesized and characterized by Fourier transform infrared, ¹H and ¹³C nuclear magnetic resonance, mass spectrometry and elemental (CHN) analysis. The in vitro antibacterial (6a–n and 7a–l) and cytotoxic (6a–n) activities were evaluated for these compounds. The results revealed that the compounds 6b, 6i, 6k, 7b, 7h displayed good antibacterial activity. The compounds 6c (IC₅₀ = 5.4 μM), 6l (IC₅₀ = 6.3 μM) and 6f (IC₅₀ = 9.85 μM) were effective for inhibition of human breast cancer cell line MCF-7. Similarly, the compounds 6b (IC₅₀ = 8.7 μM) and 6c (IC₅₀ = 9.06 μM) were shown to have effective inhibition on human cervical cancer cell line Hela.     

Dimerisation des polyphenyl-allenes—I : Chloropolyphenyl-allenes: mecanisme de la reaction “Rubrenique”

Dimerization of chloropolyphenylallenes 1a-c occurs via bisallyl diradicals 2a-c, the closure of which leads either to 1,2-dialkylidene cyclobutanes 8b,c, or to the dihydronaphthalenic compounds 3a-c which afford after elimination of HCl and cyclization the naphthocyclobutenes 5a-c. The latter, by opening and cyclization involving a further loss of HCl, are readily transformed in high yields into the naphthacenes 7a-c Some 1,2-dialkylidene cyclobutanes 8 can also lead to naphthacenes 7 through thermal opening to give diradicals 2, followed by cyclization. This multi-step process furnishes a general explanation for the so-called “rubrene” reaction (the common name of 5,6,11,12-tetraphenyl naphthacene), a route to naphthacenes starting from polyphenyl propargylic compounds which behave as aliene precursors.     

Novel pyrimidine and its triazole fused derivatives: Synthesis and investigation of antioxidant and anti-inflammatory activity

In the present study, we have carried out the synthesis of novel dihydropyrimidinecarbonitrile (1a–c), its dimethylated adduct (2a–c), and hydrazine derivative (3a–c) of 2a–c and its triazole fused derivatives (4a–c, 5a–c and 6a–c). The structure of newly synthesized compounds was confirmed by IR, ¹H NMR, mass spectral data and elemental analysis. Further the novel derivatives were investigated for their in vitro antioxidant and anti-inflammatory activity. The results revealed that some of the tested compounds showed potent antioxidant and anti-inflammatory activity. The mass spectral pattern of 6a has been investigated in order to elucidate the structure.     

Synthesis and characterization of new cyclotriphosphazene compounds

In the present study, spiro (1a), dispiro (1b, 2, 3), per-substituted spermine-bridged (6–9) and dispiroansa spermine (10) derivatives of cyclotriphosphazene have been synthesized. The structures of the novel compounds (1b, 6–10) have been characterized by elemental analysis, FTIR, mass spectrometry, ¹H and ³¹P NMR spectroscopy. The molecular structures of 1b, 2, 8, and 10 were determined by single crystal X-ray crystallography. In order to investigate the anti-tumour properties of the newly synthesized cyclotriphosphazene derivatives, in vitro cytotoxic activity test (MTT assay) has been performed using HT-29 (human colon adenocarcinoma) and Hep2 (human epidermoid larynx carcinoma) cell lines. The result of the MTT assay showed that while compound 1a has cytotoxic effect on both Hep2 and HT-29 cell lines, compound 3 has only cytotoxic effect towards the Hep 2 cells.     

Discovery of novel indene-based hybrids as breast cancer inhibitors targeting Hsp90: Synthesis,bio-evaluation and molecular docking study

Inhibition of Heat-shock protein 90 (Hsp90) is considered an attractive route in fighting against cancer proliferation. Herein, new indene derivatives targeting Hsp90 were synthesized, and biologically evaluated. The new series of indeno-pyrimidine and indeno-pyridine were synthesized from the reaction of indene-enaminone with various heterocyclic amines and active methylene derivatives. Two breast cancer cell lines were used to examine the new compounds in vitro for their anticancer activity, namely, MCF-7 and MDA-MB231 cancer cells. The new indene derivatives 8a-c, 17a, and 25 displayed significant antitumor effect especially on MCF-7 cell line compared to doxorubicin. Derivative 8a was further subjected to Hsp90 enzyme assay aiming to ensure the inhibitory potential of such compound on Hsp90, it displayed IC₅₀ = 18.79 ± 0.68 nM relative to Alvespimycin as a reference drug. Finally, molecular modeling of the most active compounds in the Hsp90 binding site was done presenting agreement with the in vitro anti-Hsp90 activity.     

Synthesis and pharmacological evaluation of 3-diphenylmethyl-6-substituted-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles: A condensed bridgehead nitrogen heterocyclic system

A series of 3-diphenylmethyl-6-substituted-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole derivatives (4a–j and 5a–d) were synthesized by condensation of 4-amino-5-diphenylmethyl-4H-1,2,4-triazole-3-thiol with various substituted aromatic acids and aryl/alkyl-isothiocyanates. The structures of synthesized compounds were characterized by elemental analysis, IR, ¹H NMR, ¹³C NMR and mass spectroscopic studies. These compounds were tested in vivo for their anti-inflammatory activity. The compounds which showed activity comparable to the standard drug ibuprofen were screened for their analgesic, ulcerogenic, lipid peroxidation and hepatotoxic effects. Compounds 6-(4-chlorophenyl)-3-diphenylmethyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (4a) and 6-(2,4-dichlorophenyl)-3-diphenylmethyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole(4c) emerged as the most active compounds of the series and were moderately more potent than the standard drug ibuprofen.     

Gold-catalyzed oxazoles synthesis and their relevant antiproliferative activities

Nine 5-aryl-2-methyloxazole derivatives were synthesized via gold-catalyzed alkyne oxidation. All of the compounds have been screened for their antiproliferative activities against MCF-7 cell （human breast carcinoma）, A549 cell （human lung carcinoma） and Hela cell （human cervical carcinoma） lines in vitro. The results revealed that compounds 1b, 1c and 1d exhibited strong inhibitory activities against the MCF-7 cell lines （with ICso values of 4.6, 9.7 and 2.2 μmol/L, respectively）.