2,4-Dihydro-3H-1,2,4-triazol-3-ones as anticonvulsant agents

A series of 5-aryl-2,4-dihydro-3H-1,2,4-triazol-3-ones was evaluated for anticonvulsant activity. In general the members of this series were prepared by the alkaline cyclization of 1-aroyl-4-alkylsemicarbazides. The resulting 2-unsubstituted 3H-1,2,4-triazol-3-ones were then alkylated, yielding 2,4-dialkyl-3H-1,2,4-triazol-3-ones. Approximately one-third of the compounds examined exhibited activity against both maximal electroshock- and pentylenetetrazole-induced seizures in mice. Receptor-binding studies suggest that this activity was not a consequence of activity at either benzodiazepine or NMDA-type glutamate receptors. From this series, compound 45 was selected for further evaluation where it was also found to be active against 3-mercaptopropionic acid, bicuculline, and quinolinic acid induced seizures in mice. In addition, 45 also protected gerbils from hippocampal neuronal degeneration produced by either hypoxia or intrastriatal quinolinic acid injection.     

Synthesis of 1-(3-amino-2-hydroksypropyl)-4-phenyl-1,2,4-triazolin-5-one and 1-(3-amino-2-hydroksypropyl)-3,4-diphenyl-1,2,4-triazolin-5-one derivatives

In the reaction of 4-phenyl-1,2,4-triazolin-5-one [Ia] and 3,4-diphenyl-1,2,4-triazolin-5-one [Ib] with 1-chloro-2,3-epoksypropane, the respective derivatives of 1-(2,3-epoksypropane)-4-phenyl-1,2,4-triazolin-5-one [IIa] and 1-(2,3-epoksypropane)-3,4-diphenyl-1,2,4-triazolin-5-one [IIb] were obtained. Then these compounds were converted into the corresponding aminoalkanol derivatives of 1,2,4-triazolin-5-one [IIIa, b-VIIIa, b] in reaction with secondary amines. The new compounds affected significantly the central nervous system of mice.     

4-Cyclohexyl-1-substituted-4H-[1,2,4]triazolo [4,3-a] quinazolin-5-ones: novel class of H1-antihistaminic agents

A series of novel 1-substituted-4-cyclohexyl-4H-[1,2,4]triazolo [4,3-a] quinazolin-5-ones were synthesized by the cyclization of 3-cyclohexyl-2-hydrazino-3H-quinazolin-4-one with various one carbon donors. When tested for their in vivo H1-antihistaminic activity on guinea-pigs, all the test compounds protected the animals from histamine induced bronchospasm significantly. The compound 4-cyclohexyl-1-methyl-4H-[1,2,4]triazolo[4,3-a] quinazolin-5-one (II) emerged as the most active compound of the series and it is more potent (72.96% protection) when compared to the reference standard chlorpheniramine maleate (71.00% protection). The compound II shows negligible sedation (9%) when compared to chlorpheniramine maleate (30%). Hence, it could serve as prototype molecule for further development as a new class of H1-antihistamines.     

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 of 1-(3-aminopropyl)-4-phenyl-1,2,4-triazolin-5-one and 1-(3-aminopropyl)-3,4-diphenyl-1,2,4-triazolin-5-one

The reaction of 4-phenyl-1,2,4-triazolin-5-one [Ia] and 3,4-diphenyl-1,2,4-triazolin-5-one [Ib] with 1-bromo-3-chloropropane was carried out. The obtained compounds [IIa, b] were subjected to the reaction with secondary amines and ethylenediamine with resulted in 1-(3-aminopropyl)-1,2,4-triazolin-5-one derivatives.     

Synthesis of 5-(2-,3- and 4-methoxyphenyl)-4H-1,2,4-triazole-3-thiol derivatives exhibiting anti-inflammatory activity

New S-alkylated 5-(2-,3- and 4-methoxyphenyl)-4H-1,2,4-triazole-3-thiols (5a-c, 6a-c) and 5-(2-,3- and 4-methoxyphenyl)-4-phenyl-4H-1,2,4-triazole-3-thiols (7a-c, 8a-c, 9a-c) were synthesized by the alkylation of 3-(2-,3- and 4-methoxyphenyl)-4,5-dihydro-1H-1,2,4-triazole-5-thiones (3a-c) or 3-(2-,3- and 4-methoxyphenyl)-4-phenyl-4,5-dihydro-1H-1,2,4-triazole-5-thiones (4a-c) with 1-iodobutane or 1-(1,3-benzodioxol-5-yl)-2-bromo-1-ethanone, 2-bromo-1-(2,3-dihydro-1,4-benzodioxin-6-yl)-1-ethanone and 2-bromo-1-(3,4-dihydro-2H-1,5-benzodioxepin-7-yl)-1-ethanone. Compounds 3a-c and 4a-c were synthesized by the acylation of thiosemicarbazide or 4-phenyl-3-thiosemicarbazide with 2-, 3- and 4-methoxybenzoyl chlorides and further cyclization of the obtained acylderivatives 1a-c and 2a-c. The synthesized compounds 4a-c, 5a, 6a-c, 7a-c, 8a-c, 9b,c exhibit anti-inflammatory activity.     

Synthesis of some new biologically active thiadiazolotriazinones--part III

4-Amino-6-arylmethyl/tert-butyl-3-mercapto-1,2,4-triazin-5(4H)-ones (1) were condensed with arylfuroic acids (2) to yield 7-(5-aryl-2-furyl)-3-arylmethyl/tert-butyl-4H-1,3,4-thiadiazolo[2,3-c]-1,2,4-triazin-4-ones (3). The newly synthesized compounds exhibited antibacterial activity comparable to that of nitrofurazone. In addition, two compounds displayed in vitro antitumor activity with moderate growth inhibition against a panel of 60 tumor cell lines.     

The reactions of cyclization of semicarbazide derivatives of 1,3-diphenyl-1,2,4-triazolin-5-thione-4-acetic acid

In the reaction of hydrazide of 1,3-diphenyl-1,2,4-triazolin-5-thione-4-acetic acid with isocyanates. semicarbazide derivatives of 1,3-diphenyl-1,2,4-triazolin-5-thione-4-acetic acid [I-X] were obtained. Cyclization of these compounds in the presence of 2% NaOH led to the formation of derivatives of 1,2,4-triazolin-5-one [XI-XX].     

Synthesis of amides of 2,4-dioxothiazolidin-5-yl acetic acid with 1,2,4-triazole substituents

In the reaction of (2,4-dioxothiazolidin-5-yl)acetyl chloride with 1,2,4-triazole, 4-phenyl-1,2,4-triazolin-5-one and 4-phenyl-1,2,4-triazolin-5-thione, the new corresponding amides (2-4) were obtained. For compounds 2 and 4 effects on central nervous system (CNS) of mice were studied.     

4-(4-烷氧基苯基)-3-乙基-1H-1,2,4-三唑-5(4H)-酮类化合物的合成及其抗惊厥活性

目的设计合成一系列4-(4-烷氧基苯基)-3-乙基-1H-1,2,4-三唑-5(4H)-酮类化合物,并评价其抗惊厥活性和神经毒性。方法以对乙酰氨基酚为起始原料,经烷基化、水解、环合等反应合成1,2,4-三唑-5(4H)-酮类化合物。通过最大电惊厥实验(MES)和神经毒性实验(NT),分别测定目标化合物的抗惊厥活性和神经毒性。结果与结论合成了20个新化合物,其结构经IR、1H-NMR和ESI-MS确证。药理学实验结果表明,所有化合物在不同剂量下都显示出抗惊厥活性。其中,3-乙基-4-(4-戊氧基苯基)-1H-1,2,4-三唑-5(4H)-酮(4e)的活性最强,其半数有效量ED50值为26.9 mg·kg-1,保护指数(PI)为11.0,虽然该化合物的活性低于阳性对照药卡马西平,但其保护指数优于卡马西平(PI=6.4);3-乙基-4-(4-(3-氟苄氧基)苯基)-1H-1,2,4-三唑-5(4H)-酮(4n)的ED50值为61.1 mg·kg-1,但其PI大于17.0,明显优于卡马西平,具有进一步研究的价值。     

Synthesis and evaluation of pharmacological and pharmacokinetic properties of 11H-[1,2,4]triazolo[4,5-c][2,3]benzodiazepin-3(2H)-ones

A series of 2,3-benzodiazepine derivatives has been previously described as noncompetitive AMPA-type glutamate receptor antagonists potentially useful for treatment of epilepsy. To further explore the structure-activity relationships of AMPA antagonists, a series of 11H-[1,2,4]triazolo[4,5-c][2,3]benzodiazepin-3(2H)-ones (6) was synthesized starting from the corresponding bicyclic 1-aryl-3, 5-dihydro-7,8-dimethoxy-4H-2,3-benzodiazepin-4-ones (2, CFM). The new compounds were found to possess anticonvulsant effects against seizures induced both by means of auditory stimulation in DBA/2 mice and by pentylenetetrazole or maximal electroshock in Swiss mice. In addition, they antagonize the AMPA-induced seizures, and their anticonvulsant activity is reversed by pretreatment with aniracetam, thus suggesting the involvement of AMPA receptors. The pharmacological studies revealed that the 11H-[1,2,4]triazolo[4, 5-c][2,3]benzodiazepin-3(2H)-ones (6) herein reported show anticonvulsant activity comparable to that of their bicyclic precursors. Furthermore, an HPLC study put in evidence that these tricyclic derivatives 6 were converted in vivo into the corresponding 2, the agents likely to be mainly responsible for the anticonvulsant properties observed.     

Synthesis of aminomethyl derivatives of 4-phenyl-1,2,4-triazolin-5-one-1-acetic acid amide and 3,4-diphenyl-1,2,4-triazolin-5-one-1-acetic acid amide

Ehtyl esters of 4-phenyl-1,2,4-triazolin-5-one-1-acetic acid and 3,4-diphenyl-1,2,4-triazolin-5-one-1-acetic acid were transformed into the corresponding amides [Ia, b]. The aminomethylation reactions afforded Mannich bases [IIa, b-VIa, b] exhibiting the expected pharmacological effects.     

Konstitutionsaufklärung der Reaktionsprodukte aus Benzonitriloxid und 1,4-disubstituierten Urazolen

Structural Elucidation of the Reaction Products from Benzonitrile Oxide and 1,4-Disubstituted Urazoles The reaction of benzonitrile oxide with 1,4-disubstituted urazoles 1 does not yield 1,4-disubstituted 3-(phenylcarbamyoloxy)--1,2,4-triazolin-5-ones 2 , as reported in the literature, but leads to N¹′,N³′-disubstituted 3-phenyl-4-ureido--1,2,4-oxadiazolin-5-ones 4 .     

Synthesis of some new biologically active thiadiazolotriazinones--Part II.

4-Amino-6-phenyl/methyl-3-mercapto-1,2,4-triazin-5(4H)-ones (1) are condensed with an aromatic carboxylic acid, aryloxyacetic acid or anilinoacetic acid (2), to yield 7-substituted-3-phenyl/methyl-4H-1,3,4-thiadiazolo-[2,3-c]-1,2,4-+ ++triazin-4- ones (3). Phosphorus oxychloride is used as a cyclizing agent. All the synthesized compounds are screened for their antibacterial activities against S. aureus, E. coli, P. aeruginosa and G. bacillus.     

Synthesis of some new biologically active bis-(thiadiazolotriazines) and bis-(thiadiazolotriazinyl) alkanes

4-Amino-3-mercapto-1,2,4-triazin-5(4H)-ones (1) were condensed with dicarboxylic acids 2 to yield bis-(4-oxo-4H-1,3,4-thiadiazolo[2,3-c]-1,2,4-triazin-7-yl)alkanes (3b-d,f-h,j-l,n-p) and bis-thiadiazolotriazines (3a,e,i,m). All the newly synthesised compounds were characterised by analytical, IR, NMR and mass spectral studies. Some of the newly synthesised compounds were screened for their antibacterial and antifungal properties. Among the tested compounds, compound 7,7'-(1,4-butanediyl)-his-(3-t-butyl-4-oxo-4H-1,3,4-thia-diazolo[2,3-c]-1,2,4-triazine (3p) exhibited highest degree of antifungal activity.     

Studies on 1,2,4-triazole derivatives as potential anti-inflammatory agents

The reaction of acetic or propionic acid hydrazides with various aryl/alkyl isothiocyanates gave thiosemicarbazides which furnished the 1,2,4-triazoles by alkali cyclization. The 4-aryl/alkyl-5-(1-phenoxyethyl)-3-[N-(substituted)acetamido]thio-4H-1,2,4-triazole derivatives were synthesized by reacting the triazoles with 2-chloro-N-(substituted)acetamide. The chemical structures of the compounds were elucidated by IR, (1)H-NMR, FAB(+)-MS spectral data and elemental analysis. In the pharmacological studies, anti-inflammatory activities of these compounds have been screened and significant activities were observed.     

Synthesis of 3-(3,4-dimethoxyphenyl)-1 H-1,2,4-triazole-5-thiol and 2-amino-5-(3,4-dimethoxyphenyl)-1,3,4-thiadiazole derivatives exhibiting anti-inflammatory activity

New 1-acylderivatives of 5-alkylthio-3-(3,4-dimethoxyphenyl)-4H-1,2,4-triazole (5c-f, 6d-f) were synthesized by the acylation of 5-alkylthio-3-(3,4-dimethoxyphenyl)-4H-1,2,4-triazoles (3, 4) with acyl chlorides. The compounds 3, 4 were obtained by the alkylation of 3-(3,4-dimethoxyphenyl)-1H-1,2,4-triazole-5-thiol (2) sodium salt with alkyl iodides. Compound 2 and 2-amino-5-(3,4-dimethoxyphenyl)-1,3,4-thiadiazole (8) were prepared by the treatment of 3,4-dimethoxybenzoylthiosemicarbazide (1) with sodium hydroxide or acetyl chloride (and then sodium hydroxide), respectively. Related 2-acylamino-5-(3,4-dimethoxyphenyl)-1,3,4-thiadiazoles (7c, e, f) were synthesized by the acylation of compound 8 with acyl chlorides. 3-(3,4-Dimethoxyphenyl)-4-phenyl-4,5-dihydro-1H-1,2,4-triazole-5-thione (9) was N-acylated with acyl chlorides or S-methylated with iodomethane to give 1-acyl-3-(3,4-dimethoxyphenyl)-4-phenyl-4,5-dihydro-1H- 1,2,4-triazole-5-thiones (10a, b) or 3-(3,4-dimethoxyphenyl)-5-methylthio-4-phenyl-4H-1,2,4-triazole (11) respectively. The synthesized compounds 6d, 7a, c, 10a, b, 11 exhibit anti-inflammatory activity.     

5-乙基-2,4-二氢-4-(2-苯氧乙基)-3H-1,2,4-三唑-3-酮的合成

丙酰肼与三光气缩合环化得到5-乙基-1,3,4-噁二唑-2(3H)-酮,继与2-苯氧乙胺反应后在碱性条件下环合得到抗抑郁药奈法唑酮中间体5-乙基-2,4-二氢-4-(2-苯氧乙基)-3H-1,2,4-三唑-3-酮,总收率66.3%.     

Synthesis of New 6-{[ω-(Dialkylamino(heterocyclyl)alkyl]thio}-3-R-2H-[1,2,4]triazino[2,3-c]quinazoline-2-ones and Evaluation of their Anticancer and Antimicrobial Activities

Several novel 6-thio-3-R-2-oxo-2H-[1,2,4]triazino[2,3-c]quinazoline-based compounds containing an ω-(dialkylamino(heterocyclyl)]alkyl fragment were synthesized to examine their anticancer activity. Some of the 6-{[ω-(hetero-cyclyl)alkyl]thio}-3-R-2H-[1,2,4]triazino[2,3-c]quinazoline-2-ones (3.1-3.10) were obtained by the nucleophilic substitution of 6-[ω-halogenalkyl]thio-3-R-2H-[1,2,4]triazino[2,3-c]quinazoline-2-ones (2.1-2.8) with azaheterocycles. Alternatively, compounds 3.1-3.22 were synthesized by alkylation of 3-R-6-thio-2H-[1,2,4]triazino[2,3-c]quinazoline-2-ones potassium salts (1.1-1.4) with (2-chloroethyl)-N,N-dialkylamine hydrochlorides or 1-(2-chloroethyl)heterocycle hydrochlorides. The structures of compounds were elucidated by (1)H, (13)C NMR, LC-MS and EI-MS analysis. Then anticancer and antibacterial, bioluminescence inhibition of Photobacterium leiognathi Sh1 activities of the substances were tested in vitro. It was found that compound 3.18 possessed a wide range of anticancer activity against 27 cell lines of cancer: non-small cell lung, colon, CNS, ovarian, renal, prostate, breast, melanoma and leukemia (log GI(50) < -5.65). The "structure-activity" relationship was discussed. COMPARE analysis for synthesized anticancer active compounds was performed.     

Synthesis and antiviral activity of 1,2,4-triazine derivatives

Interaction of 3-aryl-1,2,4-triazin-5(4H)-ones with indole and its methyl derivative in the presence of N-substituted amino acids activated with dicyclohexylcarbodiimide or ethyl chloroformate led to the formation of 1-acyl-6-indolyl-3-phenyl-1,6-dihydro-1,2,4-triazin-5(4H)-ones. The cytotoxic and antiviral actions of the 12 resulting compounds were studied using vaccinia virus.