Studies in the field of 2, 1, 3-Thiadiazole and 2,1, 3-Selenadiazole

Benzo-2, 1, 3-thiadiazole (I) undergoes chloromethylation with dichlorodimethyl ether in the presence of anhydrous aluminum chloride with the predominant formation of 4, 7-di(chloromethyl)benzo-2, 1, 3-thiadiazole (II). Bases and pseudobases (paraformaldehyde, hexamethylenetetramine, dimethylformamide) exert an inhibiting influence on this reaction. In the presence of these substances, a mixture of compound II and 4-(chloromethyl)benzo-2, 1, 3-thiadiazole (III) is formed, or else no reaction takes place. The structures of compounds II and III has been shown by their reductive decomposition to o-diamines described in the literature. The high reactivity of the chlorine in the chloromethyl group has enabled various new derivatives of benzo-2, 1, 3-thiadiazole to be obtained by its replacement with hydroxy, thiocyanato, di(-hydroxyethyl)amino, di(-chloroethyl)amino, formyl, and carboxy groups.For communication XLVIII, see [11].     

Researches on 2, 1, 3-thia- and selenadiazole

Depending on the reaction conditions, benzo-2, 1, 3-selenadiazole (I), dichlorodimethyl ether and aluminum chloride react to give a complex IV, or else 4-chloromethyl-(V) or 4, 7-di(chloromethyl) benzo-2, 1, 3-selenadiazole (VI). 5-(II) and 4-methylbenzo-2,l,3-selenadiazole(III) are chloromethylated by dichlorodimethyl ether in the presence of chlorosulfonic acid. Compound II is converted mainly into 5-methyl-4-chloromethylbenzo-2, 1, 3-selenadiazole(VII) or a mixture of three possible isomers VII, VIII, and IX, depending on the amount of base or pseudo-base in the reaction mixture. Ill gives mainly 4-methyl-7-chlorornethylbenzo-2, 1, 3-selenadiazole(X), independent of the presence of base. The structures of the chloromethylation products are shown by reductive splitting to o-diamides, and chromatography of the latter in the presence of reference spots. The high reactivity of the chlorine in the chloromethyl group made it possible to obtain new derivatives by replacing it with a hydroxyl, cyano, or thiocyano group.For Part XL see [1].     

Researches on 2,1,3-thia-and selenadiazoles

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].     

Investigations in the field of 2,1,3-thiadiazole and 2,1,3-selenadiazole

The action of sodiomalonic ester on 4-bromomethylbenzo-2,1,3-thiadiazole forms a malonate which is converted by acid hydrolysis into 4-(-carboxyethyl)benzo-2,1,3-thiadiazole. When this reaction is carried out with 5-bromomethylbenzo-2,1,3-thiadiazole, mono- and disubstituted malonic esters are formed the acid hydrolysis of which gives the corresponding acids. The nitration of 4-and 5-(-carboxyethyl)benzo-2,1,3-thiadiazoles forms, respectively, 4-(-carboxyethyl)-5,7-dinitrobenzo-2,1,3-thiadiazole and 5-(-carboxyethyl)4-nitrobenzo-2,1, 3-thiadiazole. The reaction of 4-bromomethylbenzo-2,1, 3-thiadiazole with potassium cyanide forms two products: 4-cyanomethylbenzo-2,1, 3-thiadiazole and 1,2-di(benzo-2,1, 3-thiadiazole-4-yl)-2-cyanoethane.For part LVIII, see [1].     

Fries reaction and dakin rearrangement in benzo-2,1,3-thiadiazoles

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.     

Oxidation of halohydroxybenzo-2,1,3-thiadiazoles with nitric acid

4,5-Dioxobenzo-2,1,3-thiadiazole has been synthesized. Its structure was proven by conversion to the known 4,5-dioximinobenzo-2,1,3-thiadiazole and to 2,1,3-thiadiazolo[4,5-a]phenazine, and by reduction to 4,5-dihydroxybenzo-2,1,3-thiadiazole. Oxidation of 5,6-dichloro-4,7-dihydroxy- and 5,7-dichloro-4-hydroxy-benzo-2,1,3-thiadiazoles forms 5,6-dichloro-4,7-dihydroxybenzo-2,1,3-thiadiazole, of known structure, and 7-chloro-4,5-dioxobenzo-2,1,3-thiadiazole; the latter by reaction with ortho-phenylene diamine is converted to 4-chloro-2,1,3-thiadiazolo[4,5-a]phenazine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 850–852, June, 1987.     

Oxidation and reduction of some derivatives of benzo-2,1,3-thiadiazole

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.     

Researches on 2,1,3-thia- and selenadiazole XLV. Nitration of 4-hydroxy- and 4-ethoxybenzo-2,1,3-thiadiazoIe

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].     

Researches on 2,1,3-thia- and selenadiazole XLV. Nitration of 4-hydroxy- and 4-ethoxybenzo-2,1,3-thiadiazoIe

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.     

Conversion of 4-substituted benzo-2,1,3-thiadiazoles to 5-chloro-4,7-dioxobenzo-2,1,3-thiadiazole by action of hydrogen peroxide and hydrochloric acid

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.     

平面型给-受体共轭聚合物的合成及在体异质结聚合物太阳能电池中的应用

设计合成了主链为聚2,8-{5,11-二烷基吲哚[3,2-b]咔唑}-4,7[2,5-噻吩]-二-5,6-二烷氧基-2,1,3-苯并噻二唑, 具有不同侧链的2种平面型给-受体共轭聚合物(QP-2和QP-3), 研究了其热学、光物理和光伏性质. 用聚合物-PC₇₁BM([6,6]-苯基C₇₁丁酸甲酯)共混物作为活性层构筑了本体异质结聚合物太阳能电池. 其中以QP-3为给体、以PC₇₁BM为受体的光伏电池能量转换效率最高达到2.59%, 开路电压为0.72 V, 短路电流为9.24 mA/cm², 填充因子为0.38. XRD结果表明, 平面型共轭聚合物具有较好的结晶性, 原子力显微镜(AFM)显示平面型共轭聚合物易于发生微观相分离.     

Studies in the field of 2,1,3-thia- and -selenadiazoles

The results of studies on 2,1,3-thiadiazole, benzo-2,1,3-thiadiazole, benzo-2,1,3-selenadiazole, and their derivatives by chemical, physicochemical, and physical methods give no grounds for assuming that they have a quinoid structure. These results permit the statement that these heterocycles containing quatervalent sulfur or selenium are typical heteroaromatic systems satisfying Hückel's (4n+2) rule.For part LV, see [1].     

Investigations on 2, 1, 3-thia- and selenadiazoles

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].     

Halogenation and nitration of naphtho[1,2-c][1,2,5]thiadiazole

Bromination of naphtho[1,2-c][1,2,5]thiadiazole ( I ) gives either an addition product, 4,5-dibromo-4,5-dihydronaphtho[1,2-c][1,2,5]thiadiazole ( II ), or a substitution product, 5,6-dibromonaphtho[1,2-c][1,2,5]thiadiazole ( III ), depending on the reaction conditions. Dehydrobromination of II gives 5-bromonaphtho[12-c][1,2,5]thiadiazole ( IV ). Chlorination of I gives the corresponding addition product V or 5-chloronaphtho[1,2-c][1,2,5]thiadiazole ( VI ). Compound VI can also be obtained by dehydrochlorination of V. The nitration of I produces a mixture of isomeric substitution products, 9-nitro VIII and 6-nitronaphtho[1,2-c][1,2,5]thiadiazoles ( VII ).     

Investigations of 2,1,3-thia- and selenadiazoles

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.     

Syntheses in the benzo-2, 1,3-thiadiazole series. II. Derivatives of 1,2,5-thiadiazolo]3,4-h]quinoline and benzo-2, 1, 3-thiadiazolo]4, 5-h]-1,6-naphthyridine

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.     

Studies in the field of 2,1,3-thia- and selenadiazoles

The reaction of benzo-2,1,3-thiadiazole with hydroxylamine sulfate in concentrated sulfuric acid at 150° C for 1–10 hr has been studied. It has been shown that under these conditions mixtures of different amounts of 4- and 5-aminobenzo-2,1,3-thiadiazoles are formed.For part LII, see [1].     

Disulfides of the benzo-2,1,3-thiadiazole series

Disulfides of the benzo-2,1,3-thiadiazole series were obtained by reduction of benzo-2,1,3-thiadiazolesulfonyl chlorides (by hydriodic acid or by sulfur dioxide) or by the reaction of benzo-2,1,3-thiadiazolesulfinic acids with hydrogen bromide in acetic acid. Convenient methods for the synthesis of the starting compounds were found, and the fungicidal activity of the disulfides obtained was studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1555–1558, November, 1989.     

HETEROCYCLIC SYSTEMS CONTAINING BRIDGE HEAD NITROGEN ATOM: REACTION OF 5-MERCAPTO-4H-IMIDAZO[4,5-e]- [2,1,3]BENZOTHIADIAZOLES AND 5,6-DIAMINO[2,1,3]BENZOTHIAZOLE WITH 3-(2-BROMOACETYL)COUMARINS

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.     

Investigations of 2,1,3-thia- and selenadiazole s

All of the possible isomeric monoaminobenzo-2,1,3-selenadiazoles are formed in the reaction of benzo-2,1,3-selenadizaole 4- or 5-irethyl-, or 5,6-dimethylbenzo 2,1,3-selenadiazoles with hydroxylaminesulfate in concentrated sulfuric acid.See [1] for communication LXV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 328–330, March, 1972.