首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The Fries rearrangement of 4- and 5-acetoxybenzo-2,1,3-thiadiazoles has given 4-hydroxy-7-acetyl- and 5-hydroxy-4-acetylbenzo-2,1,3-thiadiazoles, which on oxidation afford mixtures of 5-chloro-4,7-dioxo- and 5,6-dichloro-4,7-dioxobenzo-2,1,3-thiadiazole and of 6-chloro-4,5-dioxo- and 6,7-dichloro-4,5-dioxobenzo-2,1,3-thiadiazole. Reaction of 6,7-dichloro-4,5-dioxobenzo-2,1,3-thiadizole with ortho-phenyl-enediamine gives 4,5-dichloro-2,1,3-thiadiazolo[4,5-a]phenazine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1683–1687, December, 1987.  相似文献   

2.
Chlorination of benzo-2,1,3-thiadiazole (I) in the presence of iron and paraform gives only 4-chlorobenzo-2,1,3-thiazole. Chlorination of 5,6-dimethylbenzo-2,1,3-thiadiazole (II) under exactly the same conditions gives only 5,6-dimethyl-4,7-dichlorobenzo-2,1,2-thiadiazole. Similarly chloromethylation of II in the presence of paraform gives only 5,6-dimethly-4,7-di(chloromethyl)benzo-2,1,3-thiadiazole. Chlorination and chloromethylation of I proceed through the intermediate formation of monosubstituted compounds which change into disubstimted ones.It is known [2,3] that Chlorination of benzo-2,1,3-thiadiazole (I) and its 5,6-dimethyl derivative (II) with chlorine in the presence of iron gives mainly the 4,7-dichloro substitution products III and IV respectively.It was previously shown [4] that chloromethylation of I with dichlorodimethyl ether in the presence of anhydrous aluminum chloride also gives mainly 4,7-di(chloromethyl)benzo-2,1,3-thiadiazole (V). Bases and pseudo-bases (paraform, urotropine. dimethylformamide) have a retarding effect on chloromethylation. When the reaction is run in the presence of these latter the products comprise besides V, 4-chloromethyl-2,1,3-thiadiazole (VI), or else, if enough base is added, there is no reaction.For Part XLII see [1].  相似文献   

3.
In the reduction of 4-hydroxy-7-phenylazobenzo-2,1,3-thiadiazole and of 4-hydroxy-7-nitro-benzo-2,1, 3-thiadiazole with sodium hydrosulfite, 7-amino-4-hydroxybenzo-2,1,3-thiadiazole is obtained. The reduction of 4-hydroxybenzo-2,1,3-thiadiazole leads to 2,3-diaminophenol which forms 5-hydroxyquinoxaline with the bisulfite derivative of glyoxal. The oxidation of 4-hydroxy- and 4-aminobenzo-2,1,3-thiadiazoles with potassium dichromate in an acid medium has yielded 4,7-dioxo-4,7-dihydrobenzo-2,1,3-thiadiazole, which has been converted into 4,7-dihydroxybenzo-2,1,3-thiadiazole and 4,7-di(hydroxyimino)-4,7-dihydrobenzo-2,1,3-thiadiazole.Translated from Khimiya Geterotsikliches-kikh Soedinenii, No. 7, pp. 926–929, July, 1973.  相似文献   

4.
Nitration and nitrosation of 4-hydroxy-5-methyl-benzo-2, 1, 3-thiadiazole gives 4-hydroxy-5-methyl-7-nitro-and 4-hydroxy-5-methyl-7-nitrosobenzo-2, 1, 3-thiadiazoles. Oxidation of the latter, or of 4,7-diamino-5-methylbenzo-2,1,3-thiadiazole gives 5-methyl-4,7-dihydroxy-2, 1, 3-thiadiazole, forming derivatives with sodium bisulfite or hydroxylamine, and reduced by sodium dithionite to 5-methyl-4, 7-dihydroxybenzo-2, 1, 3-thiadiazole. The latter is also obtained by diazotizing 5-methyl-4-hydroxy-7-aminobenzo-2, 1, 3-thiadiazole, and decomposing the diazonium salt. Nitration of 4-ethoxybenzo-2, 1, 3-thiadiazole with sodium ethoxide gives 4-ethoxy-7-aminobenzo-2, 1, 3-thiadiazole, acetylated to 4-ethoxy-7-acetaminobenzo-2, 1, 3-thiadiazole.For Part XXXVII see [1].  相似文献   

5.
Under the influence of hydrogen peroxide and hydrochloric acid in acetonitrile 4-substituted benzo-2,1,3-thiadiazoles form 5-chloro-4,7-dioxobenzo-2,1,3-thiadiazole. 4-Alkoxy- and 4-[(alkoxycarbonyl)methoxy]benzo-2,1,3-thiadiazoles give, in addition, the corresponding 5,7-dichloro derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 114–117, January, 1988.  相似文献   

6.
All three possible isomeric amines are obtained by the reaction of 4- or 5-methylbenzo-2,1,3-thiadiazoles with hydroxylamine sulfate in concentrated sulfuric acid. Under similar conditions, 5,6-dimethyl-4-aminobenzo-2,1,3-thiadiazole is obtained from 5,6-dimethylbenzo-2,1,3-thiadiazole.See [1] for communication LXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 601–602, May, 1971.  相似文献   

7.
Derivatives of l,2,5-thiadiazolo[3,4-h]quinoline and benzo- 2,1,3-thiadiazolo-[4, 5-h]-1, 6-naphthyridine were synthesized from 4-aminobenzo-2, 1, 3-thiadiazole.See [1] for communication I.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 61–64, January, 1976.  相似文献   

8.
A method was developed for the synthesis of 5-carbethoxy-4-formyl-1,2,3-thiadiazole (I), its isomer (II); 5-benzoyl-4-formyl-1,2,3-thiadiazole (III), and its isomer (IV). It was demonstrated that although compounds I, III and IV with hydrazine gave 7H-1,2,3-thiadiazolo[4,5-d]-pyridazin-7-one (XXII), 7-phenyl-1,2,3-thiadiazolo[4,5-d]pyridazine (XXIII) and 4-phenyl-1,2,3-thiadiazolo[4,5-d]pyridazine (XXV), respectively; however, compound I gave its corresponding hydrazone (XXIV).  相似文献   

9.
Reaction of the potassium salt of 2-formyldimedone with hydrochlorides of 4-chloro-, 3-chloro-, 2-chloro-, 2,4-dichloro-, and 2,4-difluorophenylhydrazines gave the corresponding 2-arylhydrazinomethylene-dimedones which cyclized in acid media to 1-substituted 6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazoles. Oxidation of the latter with selenious acid gave the corresponding 4,5-dioxo-4,5,6,7-tetrahydroindazoles which were further converted into 3-aryl-5,5-dimethyl-4,5-dihydro-3H-pyrazolo[4,3-a]phenazines and 2,6-diaryl-4,4-dimethyl-4,5-dihydro-1H(3H)-indazolo[4,5-g]imidazoles.Riga Technical University, Riga LV-1658, Latvia; e-mail: marina@osi.lv. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, 533–539, April, 2000.  相似文献   

10.
2-Phenyltetrazolo[4,5-a]-1,3,4-thiadiazole ( 4 ), in its azido form, reacted with diethyl fumarate and diethyl maleate to give 2-phenyl-7-carbethoxy-5H-1,3,4-thiadiazolo[2,3-a]pyrimidin-5-one ( 5 ). To assign the structure of compound 5 , 2-phenyl-5-carbethoxy-7H-1,3,4-thiadiazolo[2,3-a]pyrimidin-7-one ( 6 ) was prepared from the reaction of 2-amino-5-phenyl-1,3,4-thiadiazole ( 7 ) with diethylacetylene dicarboxylate. Physical properties and spectral data of compound 6 were different from compound 5 . Theoretical and experimental aspects are discussed.  相似文献   

11.
Chloromethylation of 4- and 5-chlorobenzo-2,1,3-thiadiazoles with dichlorodimethyl ether in the presence of anhydrous aluminum chloride gives 4-chloro-7-chloromethyl- and 5-chloro-4-chloromethylbenzo-2, 1,3-thiadiazoles respectively. Reductive scission followed by treatment with thionyl chloride converts them to 4-chloro-7-methyl- and 5-chloro-4-methylbenzo-2,1,3-thiadiazoles; Chlorination of the latter gives 4-methyl-5,7-dichlorobenzo-2,1,3-thiadiazole. Replacement of the chlorine in the chloromethyl groups gives 4-chloro-7-hydrosymethyl-,5-chloro-4-hydroxymethyl-, 4-chloro-7-cyanomethyl-,4-chloro-7-carboxymethyl-,5-chloro-4-carboxymethylbenzo-2,1,3-thiadiazoles. Reductive scission of 4-chlorobenzo-2,1,3-thidiazole followed by treatment with sodium selenite gives 4-chlorobenzo-2,1,3-selenadiazole.Part XLIII see [1].  相似文献   

12.
A convenient route is reported for the synthesis of substituted 1,3,4-thiadiazolo[3,2-a]-1,3,5-triazine-5,7-diones and isoxazolo[2,3-a]-1,3,5-triazines. Condensation of the appropriately substituted 2-amino-1,3,4-thiadiazole and 3-aminoisoxazole with phenoxycarbonyl isocyanate provides the desired target compounds in fair yield.  相似文献   

13.
The reaction of 4-oxo-3,4-dihydroquinazolyl-and benzimidazolylacetonitriles with 2-chloro-2-quinolinecarbaldehydes and 1-aryl-5-chloro-3-methyl-1H-pyrazole-4-carbaldehydes gave the corresponding 3-(2-chloro-3-quinolyl)-2-(4-oxo-3,4-dihydro-2-quinazolyl)-2-propenenitriles and 3-(1-aryl-5-chloro-3-methyl-1H-4-pyrazolyl)-2-hetaryl-2-propenenitriles. Intramolecular cyclization of these compounds gives 15-oxo-15H-benzo[6,7][1,8]naphthyridino[2,1-b]quinazoline-6-carbonitriles, 1-aryl-3-methyl-11-oxo-1,11-dihydropyrazolo[4′,3′:5,6]pyrido[2,1-b]quinazoline-5-carbonitriles, and 1-aryl-3-methyl-1H-benzo[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyridine-5-carbonitriles.  相似文献   

14.
由1,3,4-噻二唑和1,3,5-三嗪稠合而成的1,3,4-噻二唑并[3,2.a]-1,3,5-三嗪衍生物具有广泛的生物活性,是一类重要的药用物质。本文对其在近二十年的合成方法进行了综述,重点介绍通过1,3,4-噻二唑衍生物为母体的合成方法。参考文献45篇。  相似文献   

15.
Condensation of 5-mercapto-4H-imidazo[4,5-e][2,1,3]benzothiadiazole (I) with various 3-(2-bromoacetyl)coumarins, followed by PPA cyclization of the intermediate ketones II, yielded 3-(2,8-dithia 1,3,5b, 9-tetraaza cyclopenta(b)-as-indacen-6-yl)chromen-2-ones III. Reaction of 5,6-diamino[2,1,3]benzothiadiazole with 3-(2-bromoacetyl)- coumarin in anhydrous ethanol containing fused sodium acetate gave the corresponding 2-coumarinyl 3,4-dihydro-1,4-pyrazino[5,6-e][2,1,3]benzothiadiazoles IV.  相似文献   

16.
Nitration of 4-hydroxybenzo-2,1,3-thiadiazole under conditions generally used for phenols, gave a high yield of 4-hydroxy-5-nitrobenzo-2,1,3-thiadiazole. The latter is readily reduced to 4-hydroxy-S-aminobenzo-2,1,3-thiadiazole which on treatment with orthoformic ester gives oxazolo [5,4-e]benzo-2,1,3-thiadiazole. 4-Ethoxybenzo-2,1,3-thiadiazole is nitrated under similar conditions, giving a high yield of a mixture of equal quantities of 4-ethoxy-S-nitro- and 4-ethoxy-7-nitrobenzo-2,1,3-thiadiazole.For Part XLIV see [1].  相似文献   

17.
Nitration of 4-hydroxybenzo-2,1,3-thiadiazole under conditions generally used for phenols, gave a high yield of 4-hydroxy-5-nitrobenzo-2,1,3-thiadiazole. The latter is readily reduced to 4-hydroxy-S-aminobenzo-2,1,3-thiadiazole which on treatment with orthoformic ester gives oxazolo [5,4-e]benzo-2,1,3-thiadiazole. 4-Ethoxybenzo-2,1,3-thiadiazole is nitrated under similar conditions, giving a high yield of a mixture of equal quantities of 4-ethoxy-S-nitro- and 4-ethoxy-7-nitrobenzo-2,1,3-thiadiazole.  相似文献   

18.
The reactions of 2-amino-1,3,4-thiadiazole with 1,3-dicarbonyl compounds are described. 2,4-Pentanedione gave 2-thiocyanato-4,6-dimethylpyrimidine while diethylmalonate and ethyl acetoacetate yielded 5-hydroxy-7H-1,3,4-thiadiazolo[3,2-a]pyrimidin-7-one and 7-methyl-5H-1,3,4-thiadiazolo[3,2-a]pyrimidin-5-one, respectively. The structure of the latter compound was confirmed by a synthesis of the alternative isomeric structure (5-methyl-7H-1,3,4-thiadiazolo[3,2-a]pyrirnidin-7-one) from 2-amino-1,3,4-thiadiazole and α-bromocrotonic acid.  相似文献   

19.
Chlorination and bromination of 2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-one and its N-methyl-substituted derivatives in acetic acid at 90–95°C leads to formation of the corresponding 5,6-dichloro(dibromo)-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones. Iodination of the same substrates with ICl under analogous conditions yields 6-iodo derivatives. Chlorination of 6-iodo-1,3-dimethyl-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-one is accompanied by replacement of the iodine atom by chlorine with formation of 5,6-dichloro-1,3-dimethyl-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-one. Bromination of 6-bromo- and 6-chloro-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones gives 5,6-dibromo- and 5-bromo-6-chloro-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones, respectively.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 4, 2005, pp. 586–589.Original Russian Text Copyright © 2005 by Yutilov, Lopatinskaya, Smolyar, Gres’ko.  相似文献   

20.
5-Chloro-4, 7-dioxo- and 5,6-dichloro-4,7-dioxobenzo-2,1,3-thiadiazoles were synthesized, and their reduction to the corresponding dihydroxy derivatives was studied. The bis(semicarbazone) and bis (thiosemicarbazone) of the 5-chloro derivative were obtained, and their antivirus activities were determined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1344–1346, October, 1982.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号