Sulfur nitride in organic chemistry. 9. The reaction of tetrasulfur tetranitride with benzyl ketones. Preparation of 3,4-disubstituted-1,2,5-thiadiazoles

The reaction of tetrasulfur tetranitride ( 1 ) with various aryl and alkyl benzyl ketones ( 2a-o ), oxindole ( 11 ), benzyl α-pyridyl ketone ( 12 ) and α-phenacylpyridine ( 13 ) afforded the corresponding 1,2,5-thiadiazoles ( 3a-n, 11 and 14 ). The scope and limitations of the above reaction were investigated and the evidences suggesting the radical anion mechanism are presented.     

A new synthesis of 3,4-disubstituted 1,2,5-thiadiazoles

A simple and convenient reduction of 3,4-diamino derivatives of 2,5-thiadiazole-1-oxide to the corresponding 1,2,5-thiadiazoles has been accomplished using Ph₃P and CCl₄ in dichloromethane.     

The chemistry of 1,2,5-thiadiazoles V. Synthesis of 3,4-diamino-1,2,5-thiadiazole and [1,2,5] thiadiazolo[3,4-b]pyrazines

The o-diamine, 3,4-diamino-1,2,5-thiadiazole ( 2 ), was synthesized from 3,4-dichloro-1,2,5-thiadiazole ( 3 ) hy three methods. Aqueous glyoxal cyclized 2 into [1,2,5]thiadiazolo[3,4–6]-pyrazine ( 14 ). 3,4-Dichloro-1,2,5-thiadiazole 1,1-dioxide ( 18 ) reaeted with 2 to give 1,3-dihydro-bis[1,2,5]thiadiazolo[3,4-b:3′,4′-e]pyrazine 2,2-dioxide ( 19 ). The reaction of 2 with selenium oxyehloride led to [1,2,5]selenadiazolo[3,4-c] [1,2,5]thiadiazole ( 12 ). Ring closure of 2,3-diaminoquinoxaline ( 4 ) with thionyl chloride or selenium oxychloride gave [1,2,5]thiadiazolo-[3,4-b]quinoxaline ( 21 ) and [1,2,5]selenadiazolo[3,4-b]quinoxaline ( 22 ), respectively. Sulfurous acid reduced 21 to the 4,9-dihydro derivative 23 , which was reoxidized to 21 with chloranil. Aqueous hase hydrolyzed 21 to 4 via the hydrated intermediate 24 . Aqueous glyoxal cyclized 4 to the covalent hydrate of pyrazino[2,3-b]quinoxaline ( 26 ), 27 , which was dehydrated to 26 . Compound 26 underwent rapid addition of two alcohols in a process analogous to covalent hydration.     

The ring opening of 3,4-dichloro-1,2,5-thiadiazole with metal amides. A new synthesis of 3,4-disubstituted-1,2,5-thiadiazoles

We have developed a new synthesis of 3,4-disubstituted-1,2,5-thiadiazoles. The methodology is based on the ring opening of readily available 3,4-dichloro-1,2,5-thiadiazole with metal amides to afford a stable synthon, which is then transformed into the 3,4-disubstituted-1,2,5-thiadiazole derivatives via two consecutive reactions with O-, S-, N- or C-nucleophiles.     

Polarography of some 2,1,3-benzothiadiazoles,benzofurazans, 2,1,3-benzoselenadiazoles,and 3,4-disubstituted and fused 1,2,5-thiadiazoles

The redox behavior has been determined in acetonitrile solutions at a mercury and platinum electrode for 2,1,3-benzo(group VI)diazoles, and 3,4-disubstituted and fused 1,2,5-thiadiazoles. The derivatives studied contained alkyl, phenyl, bromo, chloro, cyano, nitro, methylsulfonyl, and trifluoromethylsulfonyl groups. All ring systems and their derivatives are reversibly reduced initially in a one-electron step, to their respective radical anion, but the nitro and bromo derivatives are reduced preferentially at the substituent group. The potential at which the production of the radical anion occurred became more anodic as the electron withdrawing ability of the substituent and the number of substituents increased.     

Reaction of 3,4-disubstituted 1,2,5-oxadiazole 2-oxides with dipolarophiles : Substituent and solvent effect on the reaction courses

A variety of symmetrically or unsymmetrically 3,4-disubstituttd furoxans such as dicyano, dialkyl, diacyl, bis(phenylsulfonyl), N.N'-dialkyldicarbamoyl, 3(or 4)-methyl-4(or -3)-phenyl(or nitro, ethoxy, phenoxy, phenylthio, pyrrolidinyl, phenylsulfonyl), 3(or 4)-ethyl-4(or -3)phcnyl, and 3(or 4)-ethoxy-4(or -3)-phenylsulfonylruroxan reacted with dipolarophiles in toluene or xylene at the refluxing temperature to give nitrone-type 1,3-dipolar cycloadducts, 5-substituted 1-aza-2,8-dioxabicyclo-[3.3.0]octanes and/or 3-substituted 2-isoxazoline 2-oxides. On the other hand, some of the furoxans gave 2-isoxazolines via nitrile oxide 1,3-dipolar cycloaddition in a toluene (or xylene)-DMF solvent at the refluxing temperature.     

The chemistry of 1,2,5-thiadiazoles,IV. Benzo[1,2-c:3,4-c′:5,6-c″] tris [1,2,5] thiadiazole

Benzo [1,2-c:3,4-c′:5,6-c″] tris [1,2,5] thiadiazole (1) was synthesized from benzo [1,2-c:3,4-c′] - bis [1,2,5] thiadiazole (11) . Nitration of 11 gave compound 15 , which on direct amination gave nitroamine 17 . Reduction of 17 gave diamine 18 , and cyclization of 18 with thionyl chloride gave 1 . Diamine 18 was also cyclized with selenium oxychloride, glyoxal, 9,10-phenanthrene-quinone, and formic acid to give the compounds 4, 5, 19 , and 6 , respectively. A new procedure for the preparation of 2,1,3-benzothiadiazole (7) from o-phenylenediamine was used.     

Metallaborane reaction chemistry. Part 12. Some interactions of acetylenes and isocyanides with selected metallaboranes

Compared to the chemistry associated with the basic syntheses and structures of the metallaboranes, their reaction chemistry is relatively uninvestigated. To illustrate the potential variety of such reaction chemistry, a linked overview of some previously reported and previously unreported reactions of the nido-6-metalladecaboranes [(PPh₃)₂HIrB₉H₁₃], [(PPh₃)(Ph₂PC₆H₄)HIrB₉H₁₂], [(η⁶-C₆Me₆)RuB₉H₁₃], [(η⁶-MeC₆H₄^isoPr)RuB₉H₁₃] and [(η⁵-C₅Me₅)RhB₉H₁₃] with acetylenes and isocyanides is presented, together with some related chemistry derived from the arachno-type 4-metallanonaboranes [(PMe₂Ph)₂PtB₈H₁₂] and [(PMe₃)₂(CO)HIrB₈H₁₂]. Reductions, oligomerisations, and reductive oligomerisations of the unsaturated species are observed, as well as complete or partial incorporation of carbon and nitrogen hetero atoms into the metallaborane clusters.¹     

The reaction of sulfur with organic compounds

The most effective catalyst for thionation of cumenes to 4-aryl-1, 2-dithiol-3-thiones, have been proven to be sym-diphenylguanidine, mercury acetamide, mercaptobenzthiazole + ZnO. The way in which thionation of cumeme derivatives depends on the nature of the substituent in the aromatic ring is investigated. Eight derivatives (4 previously unknown) of 4-phenyl-1, 2-dithiol-3-thione, with a chlorine atom and an alkyl or alkoxy group in the benzene ring are synthesized and described.For previous papers see [1–6].     

Study of the reaction of sulfur with organic compounds

A study is made of the action of sulfur on halogen derivatives of iso- and n-propylbenzene, with 1–3 chlorine or bromine atoms at various places in the side chain. Reaction of sulfur with α-chlorocumene, α, β-dichlorocumene, and α, β, β-trichlorocumene and mixtures of these, proves to be a new convenient method of preparing 4-phenyl-1,2-dithio-3-thione (40% yield). Sulfuration of mono-, di- and tri-exo-halogen derivatives of n-propylbenzene gives 5-phenyl-1,2-dithiol-3-thione in 11–18% yield. For Part XII see [1].     

Study of the reaction of sulfur with organic compounds

The reaction of sulfur with phenylchloromethanes of the type (C₆H₅)_mCCl_nH_{4-m -n}(m=1–3; n3) is investigated. New simple methods of synthesizing tetraphenylthiophene (from C₆H₅CH₂Cl) and thianaphtheno [3, 2-b] thianapthene or 2-phenyl-3-chlorothianaphthene (from C₆H₅CHCl₂) are developed. All the heterocyclic sulfur compounds synthesized are oxidized to the corresponding sulfones, Diphenylchloromethane when heated with sulfur smoothly gives a high yield of tetraphenylethylene, and triphenylchloromethane treated similarly gives triphenylmethane. C₆H₅CCl₃ and (C₆H₅)₂CCl₂ undergo practically no reaction with sulfur under the conditions investigated.For Part VII see [1].     

A study of the reaction of sulfur with organic compounds

The reaction of sulfur with isomeric exo-polychloro derivatives of iso- and n-propylbenzenes containing from 4 to 6 chlorine atoms in the side chain at 200°–300° C has been studied. The reaction of sulfur with , , , -tetrachloro- and , , , , -pentachlorocumenes leads to the formation of the previously unknown thianaphtheno-[2, 3-d]-1, 2-dithiole-3-thione (yield 48%) and thionaphtheno[2,3-d]-3-chloro-1, 2-dithiolium chloride (yield 65%), respectively. The sulfuration reaction of the isomeric exo-tetrachloro-and exo-pentachloro-n-propylbenzenes leads to the formation of 4-chloro-5-phenyl-1, 2-dithiole-3-thione (yield 5–35%). The exo-hexachloro derivatives of iso- and n-bromobenzenes, on being heated with sulfur, form only resinous sulfuration products.For part XVI, see [1].     

Investigation of the reaction: of sulfur with organic compounds

A new method for synthesizing 5-aryl-1, 2-dithiol-3-thiones is worked out. It is based on sulfuration of nuclear-substituted n-propylbenzenes in the presence of mercaptobenzothiazole.For Part VIII see [1].     

A study of the reaction of sulfur with organic compounds

The reaction of sulfur with isomeric exo-polychloro derivatives of iso- and n-propylbenzenes containing from 4 to 6 chlorine atoms in the side chain at 200°–300° C has been studied. The reaction of sulfur with α, β, β, β′-tetrachloro- and α, β, β, β′, β′-pentachlorocumenes leads to the formation of the previously unknown thianaphtheno-[2, 3-d]-1, 2-dithiole-3-thione (yield 48%) and thionaphtheno[2,3-d]-3-chloro-1, 2-dithiolium chloride (yield 65%), respectively. The sulfuration reaction of the isomeric exo-tetrachloro-and exo-pentachloro-n-propylbenzenes leads to the formation of 4-chloro-5-phenyl-1, 2-dithiole-3-thione (yield 5–35%). The exo-hexachloro derivatives of iso- and n-bromobenzenes, on being heated with sulfur, form only resinous sulfuration products.     

A study of the reaction of sulfur with organic compounds

The reactions of sulfur with alip-halogen derivatives of 1,2-diphenylethane, 1,2-diphenylethylene, and tetraphenylethane have been studied. A new method for the production of tetraphenylthiophene (from C₆H₅CHClCHClC₆H₅), benzothieno[3,2-b]benzothiophene (from C₆H₅CHClCCl₂C₆H₅), and of 2-phenylbenzo[b] thiophene (from C₆H₅CHBrCHBrC₆H₅) has been developed. On being treated with sulfur, tetraphenyl-1,2-dichloroethane is converted into tetraphenylethylene. 1,2-Diphenylethylene reacts with sulfur in the presence of hydrogen bromide forming 2-phenylbenzo[b]thiophene and tetraphenylthiophene.For part XVII, see [1].     

Preparation and Electrochemical Properties of 3-Phenyl-6-aryl-1,2,4-triazolo[3,4-b][1,3,4]-thiadiazoles

Introduction Since Tang[1] firstly reported the electroluminescence of 8-hydroxyquinoline aluminium, much attention has been paid to the organic compound as electro-luminescent material. Especially, electron transport materials play an important role in organic light-emitting diode(OLED). 2-(4-Biphenyl)-5-(t-butylphenyl)-1,3,4-oxadiazole(PBD), as a kind of popular electron injection/transport materials, can improve remarkably the injection balance of electrons and holes. As a result, it can amend the properties of OLED[2,3].