Synthesis of 8-tert-Butyl-9-oxo-1,2,4-triazolo[4,5-b]-1,2,4-triazolo[3,4-c]-1,2,4-triazine

8-tert-Butyl-9-oxo-1,2,4-triazolo[4,5-b]-1,2,4-triazolo[3,4-c]-1,2,4-triazine has been synthesized by the interaction of 6-tert-butyl-3-hydrazino-1,2,4-triazolo[3,4-c]-1,2,4-triazin-5-one with formic acid. The conditions of carrying out the reaction are discussed. Spectral characteristics are given.     

Adamantylation of 3-Nitro- and 3-Ethoxycarbonyl-1,2,4-triazolo[5,1-c]-1,2,4-triazin-4-ones

Reaction of 3-nitro- and 3-ethoxycarbonyl-1,2,4-triazolo[5,1-c]-1,2,4-triazin-4-ones with 1-adamantanol (or 1-adamantyl nitrate) in concentrated sulfuric acid or with 1-bromoadamantane in sulfolane affords N-adamantyl derivatives. The adamantylation of 3-nitro-1,4-dihydro-7H-1,2,4-triazolo[5,1-c]-1,2,4-triazin-4-one yields a mixture of N⁸- and N¹-isomers that undergo interconversion in concentrated sulfuric acid along intermolecular mechanism.     

1,2,3-Triazolo[4,5-e]-1,2,4-triazolo[3,4-c]pyrimidines

Some new 1,2,3-triazolo[4,5-e]-1,2,4-triazolo[3, 4 -c]pyrimidmes were prepared starting from the corresponding 1,2,3-triazolo[4,5-d]pyrimidines via the formation of the 1,2,4-triazole ring. Thus suitable hydrazino derivatives 6 were condensed with triethyl orthoformate, triethyl orthoacetate and triethyl orthobenzoate to give the expected tricyclic derivatives 7 , 8 and 9 . Intramolecular cyclization of the ethoxycarbonylhydrazino derivatives 10 gave the tricyclic compounds 11 bearing an hydroxyl group in the 3 position. The v-triazolo-s-triazolopyrimidine derivatives were tested towards the A₁ and A_2A adenosine receptors in binding assays, but they did not show any receptor affinity.     

Synthesis of 6-aryl-3-cinchophenyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles

In recent years, fused heterocycles have been found to possess many unique properties in synthesis and pharmacology. Especially, 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles derivatives have been attracting much attention of chemists and pharmacologists because of their broad-spectrum biological activities such as antibacterial¹, hypotensive and CNS depressant² activities. We have prepared some 3,6-substituted 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles and found that these compounds exhibited antimacrobial, insecticidal and promote plant growth.^3-5 Cinchophen had been used widely as medicine in clinic,but has been obsolete in recent years due to its by-effect. In order to seek for other uses of cinchophen, as a continuation of our preceeding studies, we used cinchophen as the starting material to synthesize ten new 6-aryl-3-cinchophenyl-l,2,4-triazolo[3,4-b]-l,3,4-thiadiazoles 5a-j. Compound 1 was prepared by the reaction of cinchophen and ethanol in the presence of sulfuric acid. 1 then reacted with hydrazine hydrate in absolute ethanol to give 2 which yielded 3 on treatment with CS₂ and KOH. On refluxing of 3 with excess hydrazine hydrate, 4 was obtained. 4 reacted with various substituted benzoic acids in the presence of POCl₃ to afifort 5a-j.     

A Novel Rearrangement Cyclization of 3-Amino-2-benzyl-6-hydrazino-1,2,4-triazin-5-one

A facile ring closure reaction with the N-l nitrogen of the 1,2,4-triazine ring occurs when 3-amino-6-hydrazino-1,2,4-triazin-5-one(1) is refluxed in either acid, orthoester/dimethylformamide, carbon disulfide, cyanogen bromide or nitrous acid. 3-amino-2-benzyl-6-hydrazino-1,2,4-triazin-5-one(2), containing the benzyl group on the 2-position of 1, can not be cyclized under the above reaction conditions except refluxed with carbon disulfide in pyridine-water(1:1), which will pass through a novel rearrangement cyclization to afford a bicycloheterocyclic compound,6-amino-3-benzylmercapto-1,2,4-triazolo[3,4-f][l,2,4]triazin-8(7H)-one(3). The mechanisms of their ring closure and rearrangement cyclization will be presented in detail.     

1,2,4-三唑并[3,4-b]-1,3,4-噻二唑的合成

近年来稠杂环化合物的合成及其生物活性的研究日益成为杂环化学研究的热门课题。3,6-二取代-1,2,4-三唑并噻二唑衍生物是具有广谱生物活性的稠杂环化合物,如抗菌、消炎、杀微生物、调节植物生长、除草等,因而引起各国化学家的广泛兴趣。此类化合物的生物活性,     

On the preparation of substituted 4H- 1,3,4-thiadiazolo[2,3-c]-1,2,4-triazin-4-ones and 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles

The reaction of benzoyl isothiocyanates and methoxycarbonyl isothiocyanate with 4-amino-4,5-dihydro-3-(methylthio)-1,2,4-triazin-5-ones in acetonitrile gave several substituted 4H-1,3,4-thiadiazolo[2,3-c]-1,2,4-triazin-4-ones VIa-h instead of the expected thioureas. In addition, benzoyl isothiocyanate reacted with 4-amino-3-(methylthio)-5-(trifluoromethyl)-4H-1,2,4-triazole to give the benzoyl thiourea IX and with 4-amino-3-mercapto-5-(trifluoromethyl)-4H-1,2,4-triazole to give the bicyclic compound N-[3-(trifluoromethyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazol-6-yl]benzamide IX .     

Synthesis of 1,4-dihydroimidazo[5,1-c]-1,2,4-triazin-4-ones and imidazo[5,1-c]-1,2,4-triazoles

Azo compounds obtained by the coupling of 5-diazoimidazoles with diethyl esters of nitro-, chloro-, bromo-, and acetylaminomalonic acids under conditions of base catalysis are cyclized to give 1,4-dihydroimidazo[5,1-c]-1,2,4-triazin-4-ones or imidazo[5,1-c]-1,2,4-triazoles. The chloro, bromo, and nitro groups in the bicyclic products are readily replaced by action of nucleophiles. The imidazotriazinones are converted to chloroimidazotriazines by reaction with thionyl chloride or phosphorus oxychlorideUrals State Technical University-UPI, 620002 Yekaterinburg, Russia Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1544–1553, November, 1999.     

Synthesis, molecular structure and characterization of allylic derivatives of 6-amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]-triazin-8(7H)-one

1-Allyl- (2) and 7-allyl-6-amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H)-one (3) were obtained via the 18-crown-6-ether catalyzed room temperature reaction of 6-amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H)-one (1) with potassium carbonate and allyl bromide in dry acetone. The structures of these two derivatives were verified by 2D-NMR measurements, including gHSQC and gHMBC measurements. The minor compound 2 may possess aromatic character. A single crystal X-ray diffraction experiment indicated that the major compound 3 crystallizes from dimethyl sulfoxide in the monoclinic space group P2(1)/n and its molecular structure includes an attached dimethylsulfoxide molecule, resulting in the molecular formula C(10)H(16)N(6)O(2)S. Molecular structures of 3 are linked by extensive intermolecular N-H...N hydrogen bonding [graph set C(1)(1)(7)]. 1 Each molecule is attached to the dimethyl sulfoxide oxygen via N-H...O intermolecular hydrogen bonding. The structure is further stabilized by pi-pi stacking interactions.     

Diastereoselective synthesis of 3-tert-butyl-3,4-dihydropyrazolo[5,1-c][1,2,4]triazine-3,4-diyl dicarboxylates

The reactions of 3-tert-butyl-7-R¹-8-R²-pyrazolo[5,1-c][1,2,4]triazines (R¹ = H, Br; R² = Me, n-Bu) with N-bromosuccinimide in the presence of R³CO₂H (R³ = Me, t-Bu, Ph) afforded novel diastereomerically pure 3-tert-butyl-7-R¹-8-R²-3,4-dihydropyrazolo[5,1-c][1,2,4]triazine-3,4-diyl dicarboxylates. The structures of the isolated products were established on the basis of IR, ¹H, ¹³C, 2D NOESY NMR, high resolution mass spectrometry and X-ray single-crystal analysis. The steric and mechanistic origins of the observed regio- and stereoselectivity were also discussed.     

3-取代-6-吡唑基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑类衍生物的合成及生物活性

将5-取代吡唑-3-甲酸乙酯1位甲基化,经水解反应得到3种中间体1-甲基-5-取代1H-吡唑-3-甲酸（2a~2c）;以不同取代的羧酸为原料经一系列反应合成6种中间体3-取代4-氨基-5-巯基-1,2,4-均三唑（3a~3f）;将中间体（2a~2c）和（3a~3f）在三氯氧磷条件下反应,合成出18种1,2,4-三唑并[3,4-b]-1,3,4-噻二唑类化合物(4a~4r),均未见文献报道。 通过IR、1H NMR、13C NMR和元素分析表征了化合物结构。 初步的生物活性测试结果显示,所合成的化合物均表现出不同程度的生长素活性和抑菌活性。 并选取抑菌活性较好的两个化合物进行抗菌药物最低抑菌浓度(MIC)的测定。     

Synthesis and properties of 1,2,4-triazolo[4,3-d]-1,2,4-triazolo-[3,4-f]furazano[3,4-b]pyrazines

New methods for the synthesis of 1,2,4-triazolo[4,3-d]-1,2,4-triazolo[3,4-f]furazano[3,4-b]pyrazines with functional substituents of various types are proposed and some properties of these compounds are studied. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1776–1778, October, 1993.     

Synthesis of 3-pyridin-4-yl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazepines

A method for the synthesis of the previously inaccessible 3-pyridin-4-yl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazepines was developed. The X-Ray diffraction data for 8-tert-butyl-3-pyridin-4-yl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazepine are presented.     

Convenient Synthesis of Some 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles and 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines Bearing 3-Methylthio{7H-1,2,4-triazolo[1,5-d]tetrazol-6-yl}moiety as Possible Antimicrobial Activity

4-Amino-4H-3-methylthio{7H-1,2,4-triazolo[1,5-d]tetrazol-6-yl}-1,2,4-triazole-5thi-ol (1) was condensed with various substituted aromatic aldehydes or acid chlorides to yield a series of arylideneamines 2 or aroylamines 3. These were easily cyclized to the corresponding 6-aryl-3-methylthio7H-1,2,4-triazolo[1,5-d]tetrazol-6-yl-1,2,4-triazolo [3,4-b]-1,3,4-thiadiazoles (4) on treatment with palladium-on-charcoal or phosphorus oxychloride. Compounds 4 were also prepared directly via the reaction of 1 with aromatic carboxylic acids in the presence of phosphorus oxychloride. Cyclocondensation of 1 with a variety of two-carbon cyclizing reagents, namely chloroacetone, pyruvic acid, benzoylformic acid, and benzoin led to the formation of 3-methylthio{7H-1,2,4-triazolo[1,5-d]tetrazol-6-yl}-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines (5?8). Some of the newly synthesized compounds were tested for their antibacterial and antifungal activity against a variety of microorganisms.     

The Reactions of 6-(tert-Butyl)-3-hydrazino-1,2,4-triazin-5(2H)-one with Carbonyl Compounds

The reaction of 6-(tert-butyl)-3-hydrazino-1,2,4-triazin-5(2H)-one with acetone and benzaldehyde yields the corresponding hydrazones. In the presence of thionyl chloride the benzaldehyde hydrazone is converted to 3-(tert-butyl)-6-phenyl-1,2,4-triazolo[4,3-b]-1,2,4-triazin-2(1H)-one and this can also be formed via the acylation of the starting hydrazinotriazinone using benzoyl chloride.     

1,3-双[3-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑-6-基]丙烷类化合物的合成

戊二酸(1)与3-芳基-4-氨基-5-巯基-1,2,4-三唑(2a～2o)在相转移催化剂四丁基碘化铵和POCl₃作用下, 高收率合成了一系列新的1,2-双[3-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑-6-基]丙烷(3a～3o). 其结构经IR, ¹H NMR, MS和元素分析确证.     

Synthesis and reactivity of 1,2,4-triazolo[1,5-c]quinazolines

The preparation of 1,2,4-triazolo[1,5-c]quinazolines 4a-d , 5 , 8a-d by cyclocondensation of 1a-c with carboxylic acids and carboxylic anhydrides, respectively, is described. By different pathways, the 5-thioxo-5,6-dihydro-1,2,4-triazolo[1,5-c]quinazolines 4a-d react with hydrazine hydrate or amines with the formation of 5-substituted 1,2,4-triazolo[1,5-c]quinazolines 9 and 10a-d . Cyclocondensation of 9 with carboxylic acids, carboxylic anhydrides, and nitrous acid, respectively, leads to the new anellated heterocycles bis-1,2,4-triazolo[4,3-a:1,5-c]quinazoline 13 and tetrazolo [1,5-a]-1,2,4-triazolo[1,5-c]quinazoline ( 14 ).