Chemotherapeutical agents. VII. Synthesis and pesticidal activities of sulphides and sulphones derived from bis[4-aryl-1,2,4-triazoline-5-thione-3-yl]alkane and 5-phenyl-1,3,4-oxadiazole-2-thione

The bis[4-aryl-3-alkylthio-1,2,4-triazol-5-yl]alkanes 4 were prepared by the action of alkyl halides on bis[4-aryl-1,2,4-triazoline-5-thione-5-yl]alkanes in aqueous sodium hydroxide (5%). The prepared sulphides 4 were oxidised to give the corresponding sulphones 5 either with acidic potassium permanganate or hydrogen peroxide. Similarly, sulphides 8 were prepared from 5-phenyl-1,3,4-oxadiazole-2-thione by reaction with different alkylhalides in alkaline medium. Mannich bases 9 from 5 -phenyl-1,3,4-oxadiazole-2-thione (7) were also prepared by stirring an equimolar solution of 6 in ethanol with formaldehyde (38%) and an amine in an ice-cold bath. All the compounds were screened for their pesticidal activities but none showed any significant activity.     

Synthesis of heterocycles. Part VI. Synthesis and antimicrobial activity of some 4-amino-5-aryl-1,2,4-triazole-3-thiones and their derivatives

4-Amino-5-aryi-1,2,4-triazole-3-thiones I react with acid chlorides to yield 4-acylamino-5-aryl-1,2,4-triazole-3-thiones II. Compounds I also react with methylene iodide, chloroacetonitrile and methyl bromoacetate to give bis-(4-amino-5-aryl-1,2,4-triazol-3-ylthio)methanes III, 4-amino-5-aryl-3-cyanomethylthio-1,2,4-triazoles IV and 4-amino-5-aryl-3-carbomethoxymethylthio-1,2,4-triazoles V, respectively. Compounds V react with hydrazine hydrate to give the corresponding acid hydrazides VI which in turn condenses with acid chlorides and aldehydes to afford respectively 1-[(4-amino-5-aryl-1,2,4-triazol-3-ylthio)acetyl]-2-aroylhydrazines VII and aryl methylene (4-amino-5-aryl-1,2,4-triazol-3-ylthio)acethydrazones VIII. The antimicrobial activities of the above compounds were screened against different strains of bacteria and fungi.     

Synthesis of 3-arylsulfonylmethyl-1,2,4-oxadiazole-5-carboxylic acid derivatives

Several new 3-arylsulfonylmethyl-1,2,4-oxadiazole-5-carboxylic acid derivatives have been synthesized. A typical example, 3-[(4-chlorophenylsulfonyl)methyl]-1,2,4-oxadiazole-5-carboxylic acid ethyl ester ( 2c ), was prepared from the reaction of 2-(4-chlorophenylsulfonyl)acetamide oxime ( 1c ) with ethyl oxalyl chloride. The hydrazide derivative ( 3f ) showed antihypertensive activity in rats. Various structural modifications to improve activity are discussed.     

Nitrosation of methyl 2-acylamino-3-dimethylaminopropenoates. A simple conversion of n-acylglycines into 5-substituted 1,2,4-Oxadiazole-3-carboxylates

A novel simple synthesis of 5-substituted-1,2,4-oxadiazole-3-carboxylates 5 from N-acylglycines 1 , which are transformed with DMF in the presence of phosphorus oxychloride into 2-substituted-4-dimethyl-aminomethyleneoxazol-5(4H)-ones 2 , followed by opening into 2-aroylamino-3-dimethylamino-propenoates 3 , and nitrosation to give the oximes 4 as intermediates, which cyclize spontaneously into 5-substituted-1,2,4-oxadiazole-3-carboxylates 5 . The compounds 2 can be transformed into 5 without isolation of 3 and 4 .     

Synthesis, characterization and antifungal evaluation of 5-substituted-4-amino-1,2,4-triazole-3-thioesters

A series of 5-substituted-4-amino-1,2,4-triazole-3-thioesters was synthesized by converting variously substituted organic acids successively into the corresponding esters, hydrazides, 5-substituted-1,3,4-oxadiazole-2-thiols, 5-substituted-1,2,4-triazole-2-thiols and 5-substituted-1,3,4-oxadiazole-2-thioesters. Finally the target compounds were obtained by refluxing 5-substituted-1,3,4-oxadiazole-2-thioesters in the presence of hydrazine hydrate and absolute alcohol. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The synthesized compounds were evaluated for their in vitro antifungal activity. Some of the evaluated compounds possessed significant antifungal activity as compared to a terbinafine standard.     

6- and 7-aryl-1,2,4-triazolo[4,3-b]-1,2,4-triazines. Synthesis and characterization

Synthetic methods for the preparation of 6-aryl-1,2,4-triazolo[4,3-b]-1,2,4-triazines ( 1 ) and the 7-aryl isomers ( 2 ) are described. Compounds 1 were prepared from aryl glyoxaldoximes 76 via 6-aryl-1,2,4-triazin-3(2H)ones ( 75 ). A simple procedure for the preparation of the 7-aryl isomers was effected using arylglyoxals 11 and the triazoles ( 4, 12a and 12b ). However, complete regioselectivity was not realized in all cases, especially when the triazoles were substituted at the C-5 position. A regiospecific synthesis of the 7-aryl isomers 2 was developed via the 3-methylthio-5-aryl-1,2,4-triazines ( 61 ). The structure of the parent 6-phenyl derivative 5 was confirmed by x-ray crystallography.     

Electron ionization induced fragmentation of some oxadiazole and thiadiazole derivatives

The mass spectrometric behaviour under electron ionization of several 3,4-(alkyl/aryl)-disubstituted 1,2,4-oxadiazole-5(4H)-ones (1-13) and 1,2,4-thiadiazole-5(4H)-thiones (14-17), and that of 3-aryl-5-alkyl- or arylthio-1,2,4-thiadiazoles (18-24), was studied. These five-membered rings split similarly to the corresponding 1,2,4-thiadiazole-5(4H)-ones, although substitution has also a clear effect on the routes of fragmentation and the magnitude of secondary processes. In particular, the fragmentation of 1,2,4-oxadiazole-5(4H)-ones (1-6), which do not bear aromatic substituents, was, in addition to the ring ruptures, fairly complicated. The other compounds fragmented more systematically and relatively few unpredictable fragmentations occurred.     

Synthesis of new bis-1,2,4-triazole derivatives

A series of new 1,2/1,3-bis[o-(N-methylidenamino-3-aryl-5-phenyl-4H-1,2,4-triazole-4-yl)phenoxy]ethane/propane derivatives 4 were prepared in good yields by treatment of 4-amino-3-aryl-5-phenyl-4H-1,2,4-triazoles 2 with certain bis-aldehydes 1.Compounds 4 were reduced with NaBH(4) to afford the corresponding 1,2/1,3-bis[o-(N-methylamino-3-aryl-5-phenyl-4H-1,2,4-triazole-4-yl)phenoxy]ethane/propane derivatives 5. All new compounds were characterized by IR, (1)H-NMR, (13)C-NMR and mass spectral data.     

NOVEL SYNTHESIS OF CONDENSED HETEROCYCLIC SYSTEMS CONTAINING 1,2,4-TRIAZOLE RING

3-Aryl-6,7-dihydro-s-triazolo[3,4-b][1,3]thiazines and 3-aryl-5,6-dihydro-thiazolo[2,3-c]-s-triazoles were synthesized by nucleophilic substitution of 3-aryl-5-mercapto-1,2,4-triazoles with 1,3-dibromopropane and 1,2-dichloroethane. And the bis-Mannich reaction of 3-aryl-5-mercapto-1,2,4-triazoles with formaldehyde has been studied.     

3-芳基-5-巯基-1,2,4-三唑衍生物的亲核反应研究

研究了碱性条件下3-芳基-5-巯基-1,2,4-三唑与丙烯腈或丙烯酸甲酯的亲核反应,得到31个新的3-芳基-1,2,4-三唑-5-硫酮类衍生物,其结构经NMR, IR, MS和元素分析表征.     

Reaction of 4-aryl-1,2,4-triazines with hydrazine

The action of hydrazine on 3,5-dioxo-4-aryl-2,3,4,5-tetrahydro-1,2,4-triazines gave 4-amino-3,5-dixo-2,3,4,5-tetrahydro-1,2,4-triazines. The intermediates of this reaction were isolated and shown to be α-ketoacidhydra-zide 4-arylsemicarbazones and not the α-ketoanilidecarbohydrazones. The realtive rates of cyclization of the latter isomeric derivatives provide a support for a proposed intermediates which were not isolated in the reaction of 3-mercapto and 3-methylmercapto-4-aryl-5-oxo-4,5-dihydro-1,2,4-triazines with hydrazine.     

Synthesis and Transformations of 2-R-5-Aryl-5,6-dihydro-7H-[1,2,4]-triazolo[5,1-b][1,3]thiazin-7-ones

A new procedure for preparation of 2-R-5-aryl-5,6-dihydro-7H-[1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones by condensation of 5-R-1,2,4-triazole-3-thiones with 3-arylacryloyl chlorides was developed. The thiazine ring of the [1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones is easily cleaved by treating with ammonia and hydrazine affording amides and hydrazides of 3-aryl-3-(1H-1,2,4-triazol-5-ylsulfanyl)propanoic acids. The latter react with isothiocyanates furnishing carbamoyl thiohydrazides of 3-aryl-3-(1H-1,2,4-triazol-5-ylsulfanyl)propanoic acids that in alkaline media undergo cyclization into 4-aryl-5-[2-(4H-1,2,4-triazol-5-ylsulfanyl)-2-phenylethyl]-2,4-dihydro-3H-1,2,4-triazole-5-thiones.     

Ring-transformation of 1,2,4-oxadiazines. Raney nickel hydrogenation of Z-3-aryl-5,6-dihydro-5-(substituted)methylene-4H-1,2,4-oxadiazine derivatives

Raney nickel hydrogenation of Z-3-aryl-5-(ethoxycarbonyl)methylene-5,6-dihydro-4H-1,2,4-oxadiazine ( 1a-c ) affords 2-aryl-6-hydroxymethyl-4-pyrimidinone ( 2 ) and ethyl (2-aryl-4-oxazolyl)acetate ( 3 ). A similar hydrogenation of Z-5-arylcarbarnoyl)methylene-5,6-dihydro-3-phenyl-4H-1,2,4-oxadiazine ( 1d-f ) gives E-4-(arylcarbamoyl)methylene-2-phenyl-2-oxazoline ( 5 ), 4-(arylcarbamoyl)methyl-2-phenyloxazole ( 6 ), and Z-4-(aryl-carbamoyl)methylene-2-phenyl-2-oxazoline ( 7 ).     

A novel conversion of acetylenic 1,2,4-triazoles into 3-alkyl-5-arylpyridazines

Bromination of 2-aryl-1-[1,2,4]triazol-1-ylalk-3-yn-2-ols gives 6-bromo-7-hydroxy-5-alkyl-7-aryl-7,8-dihydro-[1,2,4]triazolo[1,2-a]pyridazin-4-ylium salts, which are converted by treatment with strong alkali into novel 3-alkyl-5-arylpyridazines.     

Über die Herstellung von substituierten 2,3,4,5-Tetrahydro-1,2,4-triazin-6-carbonitrilen und einige ihrer Abwandlungsreaktionen

Preparation of substituted 2,3,4,5-Tetrahydro-1,2,4-triazine-6-carbonitriles and some of its Derivatives. The synthesis of 4-substituted 2-aryl-2,3,4,5-tetrahydro-5-imino-3-oxo-1,2,4-triazine-6-carbonitriles ( 3 ), 2-aryl-2,3,4,5-tetrahydro-3, 5-dioxo-1,2,4-triazine-6-carbonitriles ( 4 ) and some 3-thioxo-derivatives thereof by a novel approach is described. In addition some possibilities for the derivatisation of these compounds are given.     

Chloro derivatives of 1,2,4-triazole

5-Substituted 3-chloro-1,2,4-triazoles were synthesized by diazotization of 5-substituted 3-amino-1,2,4-triazoles in hydrochloric acid. In addition to replacement of the amino group by a chloro group, diazotization of 5-aryl-3-aminotriazoles at high temperatures leads to chlorination of the aromatic ring.Translated from Khimiya Geterotsiklicheskikh Soedinenli, No. 3, pp. 421–423, March, 1976.     

3,3-Dinitrobutyl-1,2,4-oxadiazoles

The syntheses of 3,5-bis(3,3-dinitrobutyl)-1,2,4-oxadiazole and a series of 3-aryl-5-(3,3-dinitrobutyl)-1,2,4-oxadiazoles were accomplished by treating 4,4-dinitropentanoyl chloride with the appropriate amidoximes to yield the intermediate O-(4,4-dinitropentanoyl)amidoximes, which were dehydrated to the 1,2,4-oxadiazoles.     

The synthesis and stability of some perfluoroalkl- and perfluoroalkylene-1,2,4- and 1,3,4-oxadiazoles

5-Perfluoroalkyl-3-phenyl-1,2,4-oxadiazoles have been synthesised directly from benzamidoxime and perfluoromonoacyl chlorides. However, a more complex pattern of products was observed in the reaction between arylamidoximes and perfluorodiacyl chlorides. Depending on the conditions, the products were O, O′-perfluorodiacyl di(arylamidoximes), α, ω-bis(3-aryl-1,2,4-oxadiazol-5-yl) perfluoroalkanes and arylamidoxime (3-aryl-1,2,4-oxadiazol-5-yl)perfluorocarboxylates.     

4-Methyl-1,2,5-oxadiazole-3-carbonitrile in the synthesis of 1,2,5-oxadiazolyl-1,2,4-oxadiazoles

4-Methyl-1,2,5-oxadiazole-3-carbonitrile reacts with hydroxylamine to form 4-methyl-1,2,5-oxadiazole-3-carboxamidoxime, which turned out to be the useful starting compound in the synthesis of 3-(1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazoles.     

Synthesis of new 1,2,4-oxadiazolidin-3-ones by cycloaddition of 2-alkyl-3-aryloxaziridines with chlorosulfonylisocyanate

2-Alkyl-4-chlorosulfonyl-5-aryl-1,2,4-oxadiazolidin-3-ones 5 were prepared via cycloaddition of 2-alkyl-3-aryloxaziridines 3 with chlorosulfonylisocyanate. The structure of 5 was proved by a crystal X-ray analysis. Hydrolysis of 5 in the presence of triethylamine afforded 2-alkyl-5-aryl-1,2,4-oxadiazolidin-3-ones 6.