Studies on 1,2,3-triazoles. 10. Synthesis and antiallergic properties of 9-oxo-1H,9H-benzothiopyrano[2,3-d]-1,2,3-triazoles and their S-oxides

Selected derivatives of 9-oxo-1H,9H-benzothiopyrano[2,3-d]-1,2,3-triazole, a new heterocyclic ring system, and their S-oxides have been prepared and evaluated for antiallergic activity in the rat passive cutaneous anaphylaxis screen. Several of the compounds show intravenous potencies similar to or greater than that of disodium cromoglycate, the most potent being 6,7-dimethyl-9-oxo-1H,9H-benzothiopyrano[2,3-d]-1,2,3-triazole and its 4,4-dioxide.     

Synthesis and biological activity of some 4-substituted 1-[1-(2,3-dihydroxy-1-propoxy)methyl-1,2,3-triazol-(4 & 5)-ylmethyl]-1H-pyrazolo[3,4-d]pyrimidines

Cycloaddition of 7a, b with 6 gave, after separation and deprotection, two regioisomers 10a, b and 11a, b. The deprotected acyclic nucleoside 10a used as the precursor for the preparation of 4-amino (12), 4-methylamino (13), 4-benzylamino (14), 4-methoxy (15) and 4-hydroxy (16) analogues. All acyclic nucleosides were evaluated for their inhibitory effects against HIV-1(IIIB), HIV-2(ROD) in MT-4 cells, for their anti-tumor activity and for their inhibitory effects against Mycobacterium tuberculosis. No marked activity was found.     

Regioselective synthesis of [1]benzopyrano[4,3-c]pyrazol-4-(1H)-one and [1]benzopyrano[3,4-c]pyrazol-4(3H)-one derivatives

The cycloaddition reaction of N-phenyl-C-cinnamonitrilimine4 to coumarin leads to the formation of 3-styrylbenzopyrano[4,3-c]pyrazole derivative6, whereas 3-phenylsulfonylcoumarin 0163 0181 V 39 or 3-bromocoumarin10 or 3-cyanocoumarin11 gives 1-styrylbenzopyrano[3,4-c]pyrazole derivative7. Also, the cycloaddition of4 to 3-acetylcoumarin15 and 3-benzoylcoumarin16 gives the corresponding dihydropyrano[3,4-c]pyrazole adducts17 and18 respectively. Oxidation of17 and18 gives7.     

2,3-Dihydro-9H-isoxazolo[3,2-b]quinazolin-9-ones and 3,4-dihydro-(1,2)-oxazino [3,2-b]quinazolin-10(2H)-ones.

Two series of compounds, 2,3-dihydro-9H-isoxazolo[3,2-b]quinazolin-9-ones and 3,4-dihydro-(1,2)-oxazino-[3,2-b]quinazolin-10(2H)-ones, were synthesized and evaluated for anti-inflammatory, antipyretic and analgesic activity. The isoxazolo compounds were generally more active than their oxazino homologs. Three compounds, i.e., 2,3-dihydro-9H-isoxazolo [3,2-b]quinazolin-9-one (W-2429) and its 2- and 3-methyl congeners, were the most active of all compounds tested in this study. On the basis of the biological results herein reported, W-2429 is considerably more effective than acetylsalicylic acid in inhibiting carrageenan-induced edema and in reducing brewer's yeast-induced fever in rats. Also, it was found to be more potent than propoxyphene hydrochloride in the Randall-Selitto test for analgesic activity.     

Tricyclic heteroaromatic systems. [1]benzopyranopyrrol-4-ones and [1]benzopyrano-1,2,3-triazol-4-ones as benzodiazepine receptor ligands. Synthesis and structure-activity relationships

The synthesis, ability to displace [3H]flunitrazepam binding from bovine brain membranes, and GABA ratio of some [1]benzopyranopyrroles 1a-i and [1]benzopyrano-1,2,3-triazoles 2a,b are reported. The GABA ratios of some previously synthesized pyrazoloquinolines A and [1]benzopyranopyrazoles C are also presented in order to draw some structure-activity relationships among our benzodiazepine receptor ligands. 1,3-Diarylpyrrole derivatives 1a-h show similar affinity and efficacy to that of diazepam, while the 1-aryltriazoles 2a,b have no receptor affinity. Comparison of the latter results with those on previously reported compounds suggests that there are several hydrophobic regions on the benzodiazepine recognition site whose occupation gives rise to different affinity and efficacy.     

Researches on antiinflammatory agents. Studies on some 1-methyl- or 1-phenyl-6-(2-substitutedphenyl)-pyrazolo[3,4-d]-1,3-oxazin-4(1H)-ones.

Following our research on analgesic and antiinflammatory active compounds containing the pyrazole nucleus, a number of new 1-methyl- or 1-phenyl-6-(2-substitutedphenyl)-pyrazolo[3,4-d]-1,3-oxazin- 4(1H)-ones was synthesized and tested, together with a few analogues previously obtained, for their analgesic and antiinflammatory activities, as well as for their acute toxicity and ulcerogenic effects. One of the tested compounds showed activity comparable to that of phenylbutazone and, at the same time, higher LD50 and a very low ulceration index.     

(+/-)-2-Amino-3,4-dihydro-7-[2,3-dihydroxy-4-(hydroxymethyl)-1- cyclopentyl]-7H-pyrrolo[2,3-d]pyrimidin-4-ones: new carbocyclic analogues of 7-deazaguanosine with antiviral activity

5-Allyl-2-amino-4,6-dihydroxypyrimidine (3) was chlorinated and ozonized to yield (2-amino-4,6-dichloro-pyrimidin-5-yl)acetaldehyde (5). Acetalization of 5 with ethanol afforded a new pyrimidine intermediate 6 which can lead to 2-amino-3,4-dihydro-7-alkyl-7H-pyrrolo[2,3-d]pyrimidin-4-ones and therefore to carbocyclic analogues of 7-deazaguanosine. The 7-substituent was a cyclopentyl analogue of the arabinofuranosyl moiety in 10a, lyxofuranosyl moiety in 10b, and ribofuranosyl moiety in 10c. Compounds 10a and 10b exhibited selective inhibitory activities against the multiplication of HSV1 and HSV2 in cell culture. Repeated administration of compound 10a at 10mg/kg ip to mice infected with HSV2 increased the number of survivors and lengthened significantly the mean survival time.     

Heterocyclen via Mannichbasen, 7. Mitt. Synthese von Pyrazolo[1,5-a]pyrido[2,3-d]pyrimidin-9(4H)-onen

Heterocycles via Mannich Bases, VII: Synthesis of Pyrazolo[1,5-a]pyrido[2,3-d]pyrimidin-9(4H)-ones The title compounds 4 are synthesised from 5-amino-3-methylpyrazolo[1,5-a]pyrimidin-7(4H)-one (2) and ketone Mannich bases or dehydro Mannich bases.     

Synthesis and anti-inflammatory properties of some pyrrolo(1H,3H)[3,4-d]pyrimidin-2-ones and pyrrolo(1H,6H)[3,4-d]pyrimidin-2-ones

The unequivocal synthesis of some terms belonging to the two isomeric classes of the pyrrolo(1H,3H)[3,4-d]pyrimidin-2-ones and of the pyrrolo(1H,6H)[3,4-d]pyrimidin-2-ones is reported. Some of these compounds are active in inhibiting the development of the carrageenin edema, of the granuloma cotton pellet and of the adjuvant arthritis in the rat when administered orally.     

Redifferentiation of human hepatoma cell induced by 6-(p-chlorophenyl)-3-[1-(p-chlorophenyl)-5-methyl-1 H-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiadiazole (TDZ)

6-(p-Chlorophenyl)-3-[1-(p-chlorophenyl)-5-methyl-1 H-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiadiazole (TDZ) is a derivative of various substituted s-triazolo[3,4-b]-1,3,4-thiadiazoles, which are associated with diverse pharmacological activities. However, the antitumor activity of TDZ is not well understood. To evaluate its role on tumor cell lines, we have examined the effect of TDZ on two tumor lines: human hepatoma cell (SMMC-7721) in vitro and Sarcoma180 tumor (S180) in vivo. The cytotoxicity of TDZ on human hepatoma cells was assessed using the MTT assay. The inhibition on tumor growth was evaluated by means of trypan blue exclusion test in vitro, and using a Sarcoma180 tumor (S180) animal model in vivo. A scanning electronic microscope was used to discover the morphological changes on cell surface, cell electrophoresis was employed to determine the changes of cell surface negative charges, and alpha-fetoprotein was applied as a biomarker of hepatoma. The effect of TDZ on DNA synthesis was determined by a [3H]-thymidine incorporation assay, and cell cycle distribution by flow cytometry. The IC50 value of TDZ on SMMC-7721 cells was 52.9 microg/ml (48 h). However, TDZ could inhibit the growth of SMMC-7721 cells at concentrations far lower than the IC50 value. Treated with the same low concentrations of TDZ, microvilli on the surface of SMMC-7721 cells decreased obviously, electrophoresis rate of cells reduced from 2.14 microm ms(-1) x V(-1) x cm(-1) of control to 1.54 and 1.56 microm x s(-1) x V-1 x cm(-1), the content of AFP dropped from 205.14 +/- 6.41 ng x mg(-1) Pr to 115.68 +/- 3.47 and 78.57 +/- 2.35 ng mg(-1) Pr, and the DNA replication was inhibited by 26.8% and 45.2%. These results indicated that TDZ may inhibit proliferation of cancer cells by reversing SMMC-7721 cells malignant phenotypic characteristics and inducing redifferentiation. Flow cytometry showed that TDZ-treated cells resulted in a higher proportion of cells in S phase compared with untreated cells, and only when the concentration reached 64 microg/ml, the apoptosis could happen at the rate of 4.2%. Detection of the inhibition of Sarcoma 180 tumor growth in vivo showed that TDZ reduced the tumor weight and 69.08% of the growth was inhibited. TDZ could inhibit the proliferation of tumors in vitro and in vivo; the possible antitumor mechanism might be inducing redifferentiation at a lower dosage on vitro.     

Studies on antianaphylactic agents. 7. Synthesis of antiallergic 5-oxo-5H-[1]benzopyrano[2,3-b]pyridines

5-Oxo-5H-[1]benzopyrano[2,3-b]pyridine-3-carboxylic acids 23 and their tetrazole analogues 24 were synthesized from 4-oxo-4H-1-benzopyran-3-carbonitriles 3 or 2-amino-4-oxo-4H-1-benzopyran-3-carboxaldehydes 4. When administered intravenously, they exhibited antiallergic activity in a reaginic PCA test in rats. In the carboxylic acid series, the activity was influenced by the substituents at the 2-position and increased substantially in the following order: Me, OMe less than NH2 less than OH, H less than NHOMe. On the other hand, in the tetrazole series, 2-unsubstituted derivatives showed the highest activity. Regardless of the kinds of substituents at positions 2 and 3, compounds bearing an alkyl group, especially an isopropyl group at the 7-position, were superior in activity to the corresponding unsubstituted compounds. Among these alkyl derivatives, 3-carboxylic acid derivatives, i.e., 23c (7-ethyl), 23g (2-amino-7-isopropyl), 23r [2-(methoxyamino)-7-isopropyl], and a 3-tetrazole derivative 24c (7-isopropyl), were 41-184 times as potent as disodium cromoglycate. They also exhibited remarkable activity when administered orally; clinical studies on 23g (AA-673) are in progress.     

Synthesis,characterization and biological evaluation of 7-substituted- 4-((1-aryl-1H-1,2,3-triazol-4-yl) methyl)-2H-benzo[b][1,4]oxazin- 3(4H)-ones as anticancer agents

A series of novel 1,2,3-triazole-2H-benzo[b][1,4]oxazin-3(4H)-ones (4a–4k and 5a–5g) were designed, synthesized and screened for their anticancer activity against MCF-7 (breast) and HeLa (cervical) cell lines using [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] assay. Among all the tested compounds, 5b and 5c exhibited good cytotoxic activity against two cancer cell lines with IC₅₀ values nearer to the standard drug, cisplatin. The most active compounds 5b and 5c were further evaluated for their in vivo anticancer activity against Ehrlich Ascites Carcinoma-bearing mice and compound 5c found to possess potential cytotoxic activity as compared with the reference drug cisplatin. Molecular docking studies were also carried out to complement the experimental results.     

Synthesis and Biological Activity of New [1,3]Thiazolo[4,5-d]pyridazin-4(5H)-ones

A series of novel 2-(N-pyrrolidino, N-piperidino or N-morpholino)-7-phenyl(α-furoyl or α-thienyl)-[1,3]thiazolo[4,5-d]pyridazinones 10a–c, 14–16a,b was synthesized in 78–87% yields via the reaction of methyl 5-benzoyl(α-furoyl or α-thienyl)-2-aminosubstituted-thiazol-4-carboxylates 9a–c, 13a–e with hydrazine. These new compounds have been tested for their in vivo analgesic and anti-inflammatory activities. All compounds have been characterized by ¹H-NMR, ¹³C-NMR spectroscopy, and liquid chromatography–mass spectrometry.     

Synthesis and pharmacological investigation of novel 1-substituted-4-(4-substituted phenyl)-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-ones as a new class of H1-antihistamine agents

A series of novel 1-substituted-4-(4-substituted phenyl)-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-ones was synthesized by the cyclization of 2-hydrazino-3-(4-substituted phenyl)-3H-quinazolin-4-one with various one-carbon donors. The starting material, 2-hydrazino-3-(4-substituted phenyl)-3H-quinazolin-4-one, was synthesized from 4-substituted aniline by a novel innovative route. When tested for in-vivo H1-antihistamine activity on conscious guinea-pigs, all the test compounds significantly protected the animals against histamine-induced bronchospasm. The compound 1-methyl-4-(4-chloro phenyl)-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-one (VII) was more potent (72.71% protection), and 1-methyl-4-(4-methoxy phenyl)-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-one (II) was equipotent (71% protection), when compared with the reference standard, chlorpheniramine maleate (71% protection). Compounds II and VII showed negligible sedation (5% and 8% respectively) when compared with chlorpheniramine maleate (25%). Compounds II and VII could serve as prototype molecules for further development as a new class of H1-antihistamines.     

Synthesis and pharmacological properties of some 1-aryl-4(1H)-pyrido(2,3-d)pyrimidones.

Some 1-aryl-4(1H)-pyrido[2,3-d]pyrimidones were synthesized from the corresponding 2-anilinonicotinamides by cyclization with triethyl-orthoformate. This series of compounds is a new one with interesting antiinflammatory and hypno-sedative properties.     

Synthesis of new series of pyrazolo[4,3-d]pyrimidin-7-ones and pyrido[2,3-d]pyrimidin-4-ones for their bacterial and cyclin-dependent kinases (CDKs) inhibitory activities

Two series of pyrazolo[4,3-d]pyrimidin-7-ones and pyrido[2,3-d]pyrimidin-4-ones were designed, synthesised, and evaluated for their antibacterial activities and CDKs inhibitory activities. The pyridazine derivative: 6-phenyl-5-phenylhydrazono-2,3,4,5-tetrahydropyridazine-3,4-dione (3a) revealed activity against Staphylococcus aureus as Gram-positive bacteria while compound 2-(2-Ethoxyphenyl-5-Phenylpiperazinosulfonamido)-3H-pyrido[2,3-d]pyrimidin-4-one (13c) was showing moderate antifungal activity against Candida albicans.     

Researches on antiinflammatory agents. Studies on some new 3-(pyrazol-5-yl)-1,2,3-benzotriazin-4(3H)-ones and -quinazolin-4(3H)-ones

Following our research on analgesic and antiinflammatory active compounds containing the pyrazole nucleus, a number of 3-(pyrazol-5-yl)-1,2,3-benzotriazin-4(3H)-ones and quinazolin-4(3H)-ones was synthetized and tested. The results of tests for analgesic, antiexudative and antioedema activities, as well as for induction of lesion in the gastric mucosa, are reported and discussed.