Synthesis, anticancer evaluation of novel hybrid pyrazole-based chalcones, molecular docking, DNA fragmentation, and gene expression: in vitro studies.

A unique series of pyrazolyl-chalcone derivatives was synthesized via the method of Claisen-Schmidt condensation. The desired chalcone derivatives 7a-d and 9a-f were obtained in good yields by reacting the 4-acetyl-5-thiophene-pyrazole with the appropriate heteroaryl aldehyde derivatives. The novel chalcones have undergone complete elemental analysis, 1H-NMR, 13C-NMR, mass spectrometry, and IR characterization. The three human cancer cell lines MCF7 (human Caucasian breast adenocarcinoma), PC3 (prostatic cancer) and PACA2 (pancreatic carcinoma) as well as the normal cell line BJ1 (normal skin fibroblasts) were tested in vitro for the anti-cancer properties of the newly synthesized chalcone derivatives. When compared to the reference medicine doxorubicin (IC50 = 52.1 µM), compound 9e showed the most promise derivative (IC50 = 27.6 µM) against PACA2 cells, while compound 7d demonstrated anticancer efficacy (IC50 = 42.6 µM against MCF7 cells compared to the reference drug doxorubicin (IC50 = 48 µM). Using breast and pancreatic cell lines, the gene expression, DNA damage, and DNA fragmentation percentages for compounds 7d and 9e were evaluated. Moreover, the molecular docking study of compounds 7d and 9e was assessed. The binding affinities of compound 9e toward P53 mutant Y220C was -22 kcal per mole, while those of compound 7d towards Bcl2 and CDK4 were -27.81 and -26.9 kcal per mole, respectively, compared to the standard values (-15.82, -33.96 and -29.9 kcal per mole).

Evaluation of Pyrazolyl-Indolizine Derivatives as Antimicrobial Agents: Synthesis, In vitro, In silico ADMET and Molecular Docking Studies.

Herein, we report analogues of s-indacene by the synthesis of novel indolizine derivatives. Using chloroform as an appropriate solvent, sixteen derivatives of pyrazolyl-indolizine (4--19) were prepared by the reaction of 3-(dimethylamino)-1-(1H-pyrrol-2-yl)prop-2-en-1-one (1) with hydrazonoyl chloride derivatives (2) in the presence of triethylamine in good to excellent yields. We used NMR spectra, IR, mass spectrometry, as well as elemental analyses to prove the chemical structures and the purity of the synthesized compounds 4-19. Among all tested compounds 5, 9, 13 and 19 had a potent antimicrobial efficiency against Bacillus subtilis, Staphylococcus aureus, Pseudomonas aerginousea, Sallmonella typhemerium, and Candida albicans. Furthermore, a significant increase in lipid peroxidation (LPO) toward the Gram-negative bacteria, Pseudomonas aeruginosa when treated with compound 9 was observed, while compound 13 remarkably increased the cell membrane oxidation of Salmonella typhimurium. Additionally, we utilized docking studies and in silico methods to evaluate the drug-likeness, physicochemical properties, and ADMET profiles of the compounds. The results of the molecular docking simulation revealed that the synthesized compounds displayed decreased binding energy when interacting with the active sites of important enzymes, including Sterol 14-demethylase of C. albicans, Dihydropteroate synthase of S. aureus, LasR of P. aeruginosa, Glucosamine-6-phosphate synthase of S. typhimurium, and Gyrase B of B. subtilis.

Novel Tetrahydro-[1,2,4]triazolo[3,4-a]isoquinoline Chalcones Suppress Breast Carcinoma through Cell Cycle Arrests and Apoptosis.

Chalcones are interesting anticancer drug candidates which have attracted much interest due to their unique structure and their extensive biological activity. Various functional modifications in chalcones have been reported, along with their pharmacological properties. In the current study, novel chalcone derivatives with the chemical base of tetrahydro-[1,2,4]triazolo[3,4-a]isoquinolin-3-yl)-3-arylprop-2-en-1-one were synthesized, and the structure of their molecules was confirmed through NMR spectroscopy. The antitumor activity of these newly synthesized chalcone derivatives was tested on mouse (Luc-4T1) and human (MDA-MB-231) breast cancer cell lines. The antiproliferative effect was evaluated through SRB screening and the MTT assay after 48 h of treatment at different concentrations. Interestingly, among the tested chalcone derivatives, chalcone analogues with a methoxy group were found to have significant anticancer activity and displayed gradient-dependent inhibition against breast cancer cell proliferation. The anticancer properties of these unique analogues were examined further by cytometric analysis of the cell cycle, quantitative PCR, and the caspases-Glo 3/7 assay. Chalcone methoxy derivatives showed the capability of cell cycle arrest and increased Bax/Bcl2 mRNA ratios as well as caspases 3/7 activity. The molecular docking analysis suggests that these chalcone methoxy derivatives may inhibit anti-apoptotic proteins, particularly cIAP1, BCL2, and EGFRK proteins. In conclusion, our findings confirm that chalcone methoxy derivatives could be considered to be potent drug candidates against breast cancer.

Newly Synthesized Arylazo Derivatives Induce Apoptosis and G2/M Cell Cycle Arrest With Molecular Docking Validation in Human Cancer Cell Lines.

OBJECTIVE: We reported herein the synthesis of novel arylazo derivatives 3a-e incorporating isoquinoline moiety. METHODS: A coupling reaction of 2-(6,7-dimethoxy-3,4-dihydroisoquinolin-1-yl)acetonitrile 1 with diazotized heterocyclic amines 2 in ethanol in the presence of sodium acetate to give arylazo derivatives 3a-e. RESULTS: Cytotoxic effect of five arylazo derivatives on breast carcinoma MCF7 and hepatocellular carcinoma HepG2 was carried out, followed by molecular and functional-based assays, to estimate the anticancer effect of these compounds. The fibroblast growth factor receptor (FGFR) and epithelial growth factor receptor (EGFR) were found to interact and bind with the compounds 3a and 3d through several hydrophobic and hydrogen bonds, which were validated by molecular docking. CONCLUSION: The two promising compounds 3a and 3d demonstrated various anticancer potential activities on tumorigenesis, cytotoxicity, and apoptotic effects, exhibited in the deregulation of the expression of different genes involved in apoptotic and anti-apoptotic mechanisms, cell cycle arrest at G2/M, and induction of apoptosis in both cell lines.

Novel eco-friendly [1,2,4]triazolo[3,4-a]isoquinoline chalcone derivatives efficiency against fungal deterioration of ancient Egyptian mummy cartonnage, Egypt.

Fungal deterioration is one of the major factors that significantly contribute to mummy cartonnage damage. Isolation and molecular identification of thirteen fungal species contributing to the deterioration of ancient Egyptian mummy cartonnage located in El-Lahun regions, Fayoum government, Egypt was performed. The most dominant deteriorated fungal species are Aspergillus flavus (25.70%), Aspergillus terreus (16.76%), followed by A. niger (13.97%). A newly synthesized series of tetrahydro-[1,2,4]triazolo[3,4-a]isoquinoline chalcone derivatives were synthesized and evaluated for their antifungal activities in vitro against the isolated deteriorated fungal species (Aspergillus flavus, A. niger, A. terreus, Athelia bombacina, Aureobasidium iranianum, Byssochlamys spectabilis, Cladosporium cladosporioides, C. ramotenellum, Penicillium crustosum, P. polonicum, Talaromyces atroroseus, T. minioluteus and T. purpureogenus). The most efficient chalcone derivatives are new chalcone derivative numbers 9 with minimum inhibitory concentration (MIC) ranging from 1 to 3 mg/mL followed by chalcone derivatives number 5 with MIC ranging from 1 to 4 mg/mL.

Theoretical and molecular mechanistic investigations of novel (3-(furan-2-yl)pyrazol-4-yl) chalcones against lung carcinoma cell line (A549).

A new chalcone series has been developed that may be useful in the treatment of lung cancer. The new series was confirmed by the different spectral tools. MTT assay was used to detect the cytotoxic effect of the novel chalcones against lung cancer cell line (A549). Molecular docking studies were performed on the most two effective chalcones 7b and 7c. Different molecular techniques were utilized to study the activity and the effect of two chalcones 7b and 7c on apoptosis of A549 cell line.

[1,2,4] Triazolo [3,4-a]isoquinoline chalcone derivative exhibits anticancer activity via induction of oxidative stress, DNA damage, and apoptosis in Ehrlich solid carcinoma-bearing mice.

Despite the advances made in cancer therapeutics, their adverse effects remain a major concern, putting safer therapeutic options in high demand. Since chalcones, a group of flavonoids and isoflavonoids, act as promising anticancer agents, we aimed to evaluate the in vivo anticancer activity of a synthetic isoquinoline chalcone (CHE) in a mice model with Ehrlich solid carcinoma. Our in vivo pilot experiments revealed that the maximum tolerated body weight-adjusted CHE dose was 428 mg/kg. Female BALB/c mice were inoculated with Ehrlich ascites carcinoma cells and randomly assigned to three different CHE doses administered intraperitoneally (IP; 107, 214, and 321 mg/kg) twice a week for two consecutive weeks. A group injected with doxorubicin (DOX; 4 mg/kg IP) was used as a positive control. We found that in CHE-treated groups: (1) tumor weight was significantly decreased; (2) the total antioxidant concentration was substantially depleted in tumor tissues, resulting in elevated oxidative stress and DNA damage evidenced through DNA fragmentation and comet assays; (3) pro-apoptotic genes p53 and Bax, assessed via qPCR, were significantly upregulated. Interestingly, CHE treatment reduced immunohistochemical staining of the proliferative marker ki67, whereas BAX was increased. Notably, histopathological examination indicated that unlike DOX, CHE treatment had minimal toxicity on the liver and kidney. In conclusion, CHE exerts antitumor activity via induction of oxidative stress and DNA damage that lead to apoptosis, making CHE a promising candidate for solid tumor therapy.

Anticancer activity of novel 3-(furan-2-yl)pyrazolyl and 3-(thiophen-2-yl)pyrazolyl hybrid chalcones: Synthesis and in vitro studies.

Twelve novel chalcone derivatives were prepared using the Claisen-Schmidt condensation reaction. The reaction of 4-acetyl-5-furan/thiophene-pyrazole derivatives 5 with the corresponding aldehydes 6 afforded the targeted chalcone derivatives 7a-l in good yields. The newly synthesized chalcones were fully characterized by spectrometric and elemental analyses. The in vitro anticancer activities of the novel compounds 7a-l were evaluated against four human cancer cell lines: HepG2 (human hepatocellular carcinoma), MCF7 (human Caucasian breast adenocarcinoma), A549 (lung carcinoma), and BJ1 (normal skin fibroblasts). Compound 7g emerged as the most promising compound, with IC50 = 27.7 µg/ml against A549 cells compared to the reference drug doxorubicin (IC50 = 28.3 µg/ml), and IC50 = 26.6 µg/ml against HepG2 cells compared to the reference drug doxorubicin (IC50 = 21.6 µg/ml). The gene expression and DNA damage values and the DNA fragmentation percentages for compound 7g were determined on the lung and liver cell lines. The expression levels of the AMY2A and FOXG1 genes increased significantly (p < 0.01) in the negative samples of lung cancer cells compared with treated cells. Also, the expression values of the PKM and PSPH genes improved significantly (p < 0.01) in the negative samples compared with treated samples of liver cancer cells. The DNA damage values increased significantly (p < 0.01) in treated lung cell line samples (7g) and the positive control. The results showed a significant decrease (p < 0.05) in DNA damage values in the negative samples of liver cancer cells compared to those treated with 7g. However, the DNA fragmentation values increased significantly (p < 0.01) in the treated lung and liver cell line samples compared with the negative control.

Novel [l,2,4]triazolo[3,4-a]isoquinoline chalcones as new chemotherapeutic agents: Block IAP tyrosine kinase domain and induce both intrinsic and extrinsic pathways of apoptosis.

Two novel chemotherapeutic chalcones were synthesized and their structures were confirmed by different spectral tools. Theoretical studies such as molecular modeling were done to detect the mechanism of action of these compounds. In vitro cytotoxicity showed a strong effect against all tested cell lines (MCF7, A459, HepG2, and HCT116), and low toxic effect against normal human melanocytes (HFB4). The lung carcinoma cell line was chosen for further molecular studies. Real-time PCR demonstrated that the two compounds upregulated gene expression of (BAX, p53, casp-3, casp-8, casp-9) genes and decreased the expression of anti-apoptotic genes bcl2, CDK4, and MMP1. Flow-cytometry indicated that cell cycle arrest of A459 was induced at the G2/M phase and the apoptotic percentage increased significantly compared to the control sample. Cytochrome c oxidase and VEGF enzyme activity were detected by ELISA assay. SEM tool was used to follow the morphological changes that occurred on the cell surface, cell granulation, and average roughness of the cell surface. The change in the number and morphology of mitochondria, cell shrinkage, increase in the number of cytoplasmic organelles, membrane blebbing, chromatin condensation, and apoptotic bodies were observed using TEM. The obtained data suggested that new chalcones exerted their pathways on lung carcinoma through induction of two pathways of apoptosis. Graphical abstract Novel chalcones were prepared and confirmed by different spectral tools. Docking simulations were done to detect the mechanism of action. In vitro cytotoxicity indicated a strong effect against different cancer cell lines and low toxic effects against normal human melanocytes (HFB4). The lung carcinoma cell line was chosen for further molecular studies that include Real-time PCR, Flow-cytometry, Cytochrome c oxidase, and ELISA assay. SEM and TEM tool were used to follow the morphological changes occurred on the cell surface.

Synthesis, Cytotoxicity and Docking Simulation of Novel Annulated Dihydroisoquinoline Heterocycles.

OBJECTIVE: Coupling of ethyl 2-(6,7-dimethoxy-3,4-dihydroisoquinolin-1-yl)acetate 2 with diazotized anilines in ethanol in the presence of sodium acetate yielded 2-(2-arylhydrazono)-2-(6,7- dimethoxy-3,4-dihydroisoquinolin-1-yl)acetate (4a-f). METHODS: Treatment of 2 with α-bromoketones 6a-f in dry benzene at reflux gave the corresponding isoquinolinium bromides 7a-f. Refluxing of each of the salts 7a-f in dry benzene and in the presence of triethylamine yielded 2-arylpyrrolo-[2,1-a]isoquinoline structures 8a-f, that converted to ethyl (E)-8,9- dimethoxy-3-(phenyldiazen-yl)-2-(aryl)-5,6-dihydropyrrolo[2,1-a]isoquinoline-1-carboxylate (9a-f) upon treatment with diazotized anilines 3 in ethanol in the presence of sodium acetate. RESULTS AND CONCLUSION: Cytotoxic assay was performed for in vitro antitumor screening against caucasian breast adenocarcinoma (MCF7), hepatocellular carcinoma (HepG2) and colorectal carcinoma (HCT-116) cell lines. The results were compared with the standard anticancer drug (doxorubicin). Molecular docking using MOE 2014.09 software was carried out for the most potent compound 4d, which showed the highest binding affinity towards the four tested proteins and thus initiated apoptosis of cancer cells.

Molecular Docking Study, Cytotoxicity, Cell Cycle Arrest and Apoptotic Induction of Novel Chalcones Incorporating Thiadiazolyl Isoquinoline in Cervical Cancer.

BACKGROUND: Chalcones are naturally occurring compounds found in various plant species which are widely used for the traditional popular treatments. Chalcones are distinguished secondary metabolites reported to display diverse biological activities such as antiviral, antiplatelet, anti-inflammatory, anticancer, antibacterial and antioxidant agents. The presence of a,ß-unsaturated carbonyl group in chalcones is assumed to be responsible for their bioactivity. In addition, heterocyclic compounds having nitrogen such as isoquinolines are of considerable interest as they constitute the core structural element of many alkaloids that have enormous pharmacological activities. OBJECTIVE: The objective of this study is the synthesis and biological activity of novel chalcones incorporating thiadiazolyl isoquinoline as potential anticancer candidates. Different genetic tools were used in an attempt to know the mechanism of action of this compound against breast cancer. METHODS: An efficient one pot synthesis of novel chalcones incorporating thiadiazolyl isoquinoline was developed. The cytotoxic activity of the novel synthesized compounds was performed against four different kinds of cancer cell lines. RESULTS: Among all the tested derivatives, chalcone 3 has the best cytotoxic profile against A549, MCF7, and HeLa cell lines, with IC50s 66.1, 51.3, and 85.1µM, respectively. Molecular docking studies for chalcone 3 revealed that CDK2, and EGFRTK domains have strong binding affinities toward the novel chalcone 3, while tubulin-colchicine-ustiloxin, and VEGFRTK domains illustrated moderate mode of binding. CONCLUSION: We have developed an efficient method for the synthesis of novel chalcones incorporating thiadiazolyl isoquinoline. All compounds showed better cytotoxicity results against four kinds of cancer cell lines (A549, MCF7, HCT116, and HELA cells). The results depicted that chalcone 3 has a high and promising cytotoxic effect against HELA cell line and the mechanism of cytotoxicity was widely studied through different theoretical and experimental tools. Thus, the newly synthesized derivative 3 can be utilized as a novel chemotherapeutic compound for cervical carcinoma.

Biological Activity, Apoptotic Induction and Cell Cycle Arrest of New Hydrazonoyl Halides Derivatives.

BACKGROUND: The hydrazonoyl halides are presently an important target in the field of medicinal chemistry. The interest in the chemistry of hydrazonoyl halides is a consequence of the fact that they undergo a wide variety of reactions which provide routes to a myriad of both heterocyclic and acyclic compounds. In addition, they have diverse biological activities such as antiviral, anthelmintic, antiarthropodal, fungicidal, herbicidal, insecticidal, pesticidal, acaricidal and miticidal Activity correlated to the presence of hydrazonoyl halides. Moreover, many applications in both industrial and pharmaceutical fields have been found to be associated with these halides. Depending on the above facts and continuation to our work, we herein report on the evaluation of the anticancer activity of these two halides prepared according to the published work and trying to know their molecular mechanism that they proceed to stop proliferation and metastasis of tumor cells by molecular tools such as real time PCR using different apoptotic genes, and cell cycle assay. OBJECTIVE: The goal of this present study is to bring attention to the biological activities of hydrazonoyl halides and the molecular pathway they follow to exert their role in apoptotic death of cancer cell. METHODS: Synthesis of hydrazonoyl halides 2c and 2f. The cytotoxic effect against different human cancer cell lines PC3, HepG-2, HCT-116, MCF-7 and also on normal human cell lines as MCF-10 and MCF-12 in a monolayer culture model was evaluated. Their mechanism of action inside cancer cell was evaluated using different molecular tools. CONCLUSION: Strong and promising chemotherapeutic hydrazonoyl halides (2a-2f) were evaluated for their different biological activities. As antimicrobial agents, results indicated that three compounds 2a, 2e and 2f exhibited high activity against two tested gram positive bacteria Staphylococcus aureus, Bacillus subtilis, and gram negative ones Escherichia coli, and Pseudomonas aeruginosa, the rest of the compounds were found to be moderately active against the tested microorganisms. Regarding their antifungal effect, compound 2c exhibited potent and promising effect against Candida albicans, while 2b was the most potent toward Aspergillus flavus Link. The compound 2f has repellent effect. With respect to the in vitro antitumor screening, this was done on different human cancer cell lines; namely PC3, HepG-2, HCT-116, MCF-7 and also on normal human cell lines; as MCF-10 and MCF-12 (normal breast epithelial cell and non-tumorigenic breast epithelial cell line) in a monolayer culture model where screening has been conducted at 100µg/ml (single dose test). Single dose test (100µg/ml) showed that, in case of PC3, all compounds have cytotoxic activity over 90% inhibition, 4 compounds have cytotoxic activity with 100% inhibition with Human colon cancer cell line, 4 compounds showed over 90% inhibition with MCF7 cell line and 4 compounds showed cytotoxic activity over 90% inhibition with HepG-2. Results of IC50 values for most promising compounds showed compounds with values lower than 20µM for all tested human cancer cell line. The promising hydrazonoyl halide 2c and 2f were selected for molecular study to know how they could act inside cancer cell causing death. Two biochemical tests were performed using the two halides 2c and 2f to predict their mechanism of action against breast carcinoma. Real time PCR analysis indicates that the two compounds induced the apoptosis of MCF7 cells through the up regulation of caspase-3, BAX mediated P53 mechanism but unfortunately, they promote the expression of anti-apoptotic protein BCL2. Also, cell cycle assay was performed using two different cell lines MCF7 and HCT116 and data revealed that the two compounds 2c and 2f induced apoptotic cells death of both lines via cell growth arrest at G2/M phase. In addition, it was noted that 2c induced arrest in the two lines more efficiently than 2f at G2/M phase.

Synthesis, Cytotoxicity, Antimicrobial and Docking Simulation of Novel Pyrazolo[3,4-d]pyrimidine and pyrazolo[4,3-e][1,2,4]triazolo[3,4-c] pyrimidine Derivatives.

BACKGROUND: Isobutyrohydrazonoyl bromide 1 was used as a precursor for the synthesis of 4-imino-3-isopropyl-1-(4-nitrophenyl)-1,4-dihydro-5H-pyrazolo[3,4-d]pyrimidin-5-amine 4, which was converted into hydrazino derivative 5 by heating with hydrazine hydrate at reflux. Hydrazino, as well as imino-amino derivatives, underwent condensation and cyclization reactions to give pyrazolo[ 3,4-d]pyrimidine and pyrazolo[4,3-e][1,2,4]triazolo[3,4-c]pyrimidine derivatives, respectively. METHOD: Antimicrobial studies are performed using two-gram positive bacteria and two-gram negative bacteria. RESULTS: Data revealed that compound 9a is the most promising antibacterial agent with high efficiency (low MIC value (48 µg/ml)). The cytotoxic assay was investigated for in vitro antitumor screening against Caucasian breast adenocarcinoma MCF7, hepatocellular carcinoma HepG2 and colon carcinoma HCT-116 cell lines. CONCLUSION: The results are compared with doxorubicin standard anticancer drugs as well as normal cell lines like MCF10 and MCF12. Molecular docking was carried out for the highest potent compound 8c with the binding site of dihydrofolate reductase enzyme DHFR PDB:ID (1DLS).

Cytotoxicity, molecular modeling, cell cycle arrest, and apoptotic induction induced by novel tetrahydro-[1,2,4]triazolo[3,4-a]isoquinoline chalcones.

Novel tetrahydro-[1,2,4]triazolo[3,4-a]isoquinolin-3-yl)-3-arylprop-2-en-1-one derivatives were synthesized and their structures were confirmed by different spectral tools. Cytotoxicity test revealed that some compounds exhibited strong to moderate effect, while others showed weak action against different cancer cell lines (MCF7, A549, HCT116, and Hepg2). Breast carcinoma revealed higher sensitivity toward all derivatives especially compounds 5 and 8 which offered the lowest IC50 values (50.05, and 27.15 µg/ml) respectively, relative to the positive control 5-fluorouracil (5-FU) (IC50 = 178 µg/ml). In addition, the two compounds exhibited less toxic effect toward normal melanocytes (HFB4). Several theoretical and experimental studies were done to reveal the molecular mechanisms that control breast carcinoma metastasis using the two promising novels 5 and 8. Docking simulation studies against the two proteins EGFR and DHFR demonstrate that compound 8 showed higher binding affinity toward the two proteins more than compound 5, suggesting that trimethoxy groups may be responsible for this higher activity through the formation of five hydrogen bonding with the active domain (4r3r) and other four interactions with the active domain (1dls). Real time PCR assay illustrates that the two compounds up regulated BAX, p53, caspase-3 genes and down regulated BCL2, MMP1, CDK4 ones. In addition, it was noted that compound 8 was more effective in gene regulation and apoptotic induction than compound 5. Also, flow cytometer analysis demonstrates that both compounds 5 and 8 induced cell growth arrest at G1 phase and thus, inhibit G1/S transition and cell cycle progression. In addition, both compounds stimulate apoptotic death of breast cells significantly to reach 8.72%, and 17.28% respectively, compared to their control (0.55%). Apoptotic induction of breast cells was enhanced effectively through activation of caspase-3 by compound 8 using Elisa assay.

Synthesis and antimicrobial activity of some new pyrazole, fused pyrazolo[3,4-d]-pyrimidine and pyrazolo[4,3-e][1,2,4]-triazolo[1,5-c]pyrimidine derivatives.

Hydrazonyl bromides 2a,b reacted with active methylene compounds (dibenzoylmethane, acetylacetone, ethyl acetoacetate, phenacyl cyanide, acetoacetanilide, ethyl cyanoacetate, cyanoacetamide and malononitrile) to afford the corresponding 1,3,4,5- tetrasubstituted pyrazole derivatives 5-12a,b. Reaction of 12a,b with formamide, formic acid and triethyl orthoformate give the pyrazolo[3,4-d]pyrimidine, pyrazolo[3,4- d]pyrimidin-4(3H)one and 5-ethoxymethylene-aminopyrazole-4-carbo-nitrile derivatives 13-15a,b, respectively. Compounds 15 a,b reacted with benzhydrazide and hydrazine hydrate to afford pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine and [4-iminopyrazolo- [3,4-d]pyrimidin-5-yl]amine derivatives 16 a,b and 17 a,b. Reactions of compounds 17 a,b with triethyl orthoformate and carbon disulfide give the corresponding pyrazolo[4,3-e]- [1,2,4]triazolo[1,5-c]pyrimidine derivatives 18a,b and 19 a,b, respectively.

Synthesis and biological activity of some new pyrazoline and pyrrolo[3,4-c]pyrazole-4,6-dione derivatives: reaction of nitrilimines with some dipolarophiles.

Several 1,3-diaryl-5-(cyano-, aminocarbonyl- and ethoxycarbonyl-)-2-pyrazoline, pyrrolo[3,4-c]pyrazole-4,6-dione and 1,3,4,5-tetraaryl-2-pyrazoline derivatives were prepared by the reaction of nitrilimine with different dipolarophilic reagents. The new compounds were characterized using IR, (1)H-NMR, (13)C-NMR and mass spectra. Biological screening of some compounds is reported.

2-(4-Chlorophenyl)-1,3-dicyano-6,7-dihydro-4-imino-9,10-dimethoxybenzo[a]quinolizine-water (2/5).

Crystals of the title compound, C(23)H(17)ClN(4)O(2).2.5H(2)O, contain channels filled with highly disordered water molecules. The best structure refinement was obtained by removing the solvent contribution from the intensity data and refining against a solvent-free model. The central six-membered ring of the quinolizine molecule has a slightly distorted screw-boat conformation.