Reaktionen von Aroyl(Hetaroyl)iminodithiokohlesäureestern mit Carbanionen CH-acider Verbindungen

Reactions of Dimethyl N-Aroyl(Hetaroyl)carbimidodithioates with Carbanions CH-acidic Compounds Reactions of dimethyl N-aroyl(hetaroyl)carbimidodithioates 1 with carbanions 2 present new possibilities to synthesize 3-acyl-amino-3-methylthio-2-subst.-acrylnitriles 3 by monosubstitution of methylthiogroup. The reaction of 1 with 2-alkyl-benzothiazolium salts 4 yield deeply coloured N-acyl-(2,3-dihydrobenzothiazole-2-yliden) thioacetimido acid-methylates 5 of the 2-subst.-benzothiazoliumperchlorates 6 . The structures of the final products are determined by i.r.-, ¹H.-n.m.r.- and u.v.-spectra.     

Synthesen auf der Basis von 2-Oxoglutarsäure. II Zur Synthese von Heterocyclen durch Reaktionen von 3-Brom-2-oxoglutarsäuredimethylester mit Binucleophilen

Organic Syntheses Based on 2-Oxoglutaric Acid. II. On the Synthesis of Heterocycles by Reactions of Dimethyl 3-bromo-2-oxoglutarate with Binucleophiles Reactions of dimethyl 3-bromo-2-oxoglutarate 2 with binucleophiles to form heterocycles proceed on two different pathways depending on the type of reactant. Thus, strong S-nucleophiles like thioureas and thiocarbohydrazide substitute initially the bromine atom and form 2-aminothiazoles 3 – 7 and the 1,3,4-thiadiazine 8 . However, o-phenylendiamines reacted to form the brominated quinoxaline-2(1H)-one derivatives 9 and 10 , resp.     

Cyclisierungsreaktionen β, γ-ungesättigter Kohlensäurederivate. II. Reaktionen β, γ-ungesättigter Carbamidsäurederivate mit elektrophilen Reagenzien - Synthese von N-substituierten Oxazolidin-2-onen

Cyclization Reactions of β,γ-Unsaturated Derivatives of Carbonic Acid. II. Reactions of β,γ-Unsaturated Carbamic Acid Esters with Electrophilic Reagents — Synthesis of N-Substituted Oxazolidine-2-ones N,N-Disubstituted β,γ-unsaturated urethans have been cyclized to N-substituted oxazolidine-2-ones by dry hydrogen chloride in methylene chloride. The N-substituted urethan 1a reacts with hydrogen chloride to form the urethan 2a and the 2-oxazoline 3 Reaction of 1 with bromine yields the corresponding N-substituted 5-bromomethyl oxazolidine-2-ones 6     

Cyclisierungsreaktionen β,γ-ungesättigter Kohlensäurederivate. V . Reaktionen β,γ-ungesättigter Carbamidsäureester mit Sulfenylchloriden - Synthese von 3,5,5-trisubstituierten Oxazolidin-2-onen

Cyclization Reactions of β,γ-Unsaturated Derivatives of Carbonic Acid. V. Reactions of β,γ-Unsaturated Carbamic Acid Esters with Sulfenyl Chlorides — Synthesis of 3,5,5-Trisubstituted Oxazolidine-2-ones N,N-Disubstituted β,γ-Unsaturated urethanes 1 have been cyclized to 3,5,5-trisubstituted oxazolidine-2-ones 3 by aromatic sulfenyl chlorides in methylene chloride. The same oxazolidine-2-ones 3 were obtained by reaction of 5-bromomethyloxazolidine-2-ones 8 with thiophenols.     

Umsetzung von 2,3-Dichlormaleinimiden mit Ethoxycarbonylmethylentriphenylphosphoran und Folgereaktionen

Reaction of 2,3-Dichloromaleimides with Ethoxycarbonylmethylenetriphenylphosphorane and Secondary Reactions 2, 3-Dichloromaleimide 1a reacts with ethoxycarbonylmethylenetriphenylphosphorane under alkenylation to give 3, 4-dichlor-5-ethoxycarbonylmethylidene-3-pyrrolin-2-one 2 . With N-substituted 2, 3-Dichloromaleimides 1b–1f one chloroatom is substituted to give 2-(ethoxycarbonyltriphenylphosphoranyl)-methylene-3-chloro-maleinimides 3 . The reactions of 2 and 3a with various nucleophiles are investigated.     

Darstellung und Reaktionen von α-Halogenbenzyl-silanen

Preparation and Reactions of α-Halogenobenzyl-silanes α-Bromobenzyl-dimethylchlorosilane 3 , bis-(α-bromobenzyl)-dimethylsilane 8 and the corresponding α-chlorobenzyl-compounds 5 and 13 have been prepared by reaction of benzyl-dimethylchlorosilane 1 resp. dibenzyl-dimethylsilane 2 with N-bromosuccinimid and sulfurylchlorid. The α-halogenobenzyl-dimethylchlorosilanes 3 and 5 have been treated with water, alcohols and phenol, to give the corresponding silanols 15 and 16 , siloxanes 17 and 18 , alkoxy- and phenoxysilanes 19 and 20 . Reactions of 3 with brenzcatechin, o-aminophenol and o-aminobenzylalcohol give 6- resp. 7- membered silaheterocycles 21 – 23 .     

1,3-Dithienium- und 1,3-Dithioleniumsalze. IX. Reaktionen von 1,3-Dithian-2-ylium-tetrafluoroboraten mit C-Nucleophilen

1,3-Dithienium and 1,3-Dithiolenium Salts. IX. Reactions of 1,3-Dithiane-2-ylium Tetrafluoroborates with C-Nucleophiles 1,3-Dithian-2-ylium tetrafluoroborates ( 1 ), which can be easily obtained by variable methods, react in good to excellent yields with variable C-nucleophiles to new geminal disubstituted 1,3-dithianes. The latter compounds are potential precursors of interesting synthetic building blocks. Reactions are described with 2-lithio-1,3-dithianes 2 , sodium cyanide 4 , sodium salts of the nitro alkanes 7 and CH-acids of the type of the 1,3-dicarbonyl compounds 9 . The reduction of 3-oxo-2-(2-phenyl-1,3-dithian-2-yl)-ethoxybutanoat–following a diastereoselective pathway – leads to the Cram product 11 . Further presented is the crystal structure of 2-phenyl-1,3-dithiane-2-ylium tetrafluoroborate ( 1b ).     

Reaction of isoprene with phenols catalysed by nickelocene and phenylmagnesium bromide

The reaction of isoprene with phenol, catalysed by nickelocene and phenylmagnesium bromide, yields 2,2-dimethylchroman, 2-(3′-methyl-2′-buten-1′-yl)phenol, 4-(3′-methyl-2′-buten-1′-yl)phenol, 2,2-dimethyl-8-(3′-methyl-2′-buten-1′-yl)chroman and 2,2-dimethyl-6-(3′-methyl-2′-buten-1′-yl)chroman. Reactions with other phenols were examined.     

Reaktionen mit Thio-bis-formamidinen

Reactions with Thio-bis-formamidines N,N,N′-Trisubstituted S-(4-amino-s-triazin-2-yl)-isothioureas 3 are prepared in good yields form trisubstituted thio-bis-formamidine-hydrochlorides 1 and esters of cyanimidocarboxylic acids 2 . In aqueous alkali solutions compounds 1 react with β-dicarbonyl compounds under rearrangement to yield substituted N-(pyrimidin-2-yl)-thioureas 4 and 5 .     

Phase transfer catalysed alkylation of enamines of β-keto carbothionic acid anilides with dihalogenoalkanes: Synthesis of Cyclic S,N-Acetals of α-Oxo Ketene

Alkylation of 2-morpholino-cycloalken-1-carbothionic acid anilides 1 and 2 with 1,3-dibromopropane in a two-phase system leads to 1-morpholino-cycloalken-3-aryl-tetrahydro-1,3-thiazine-2-ylidene 3 and 4 . Reactions of 2-morpholino-cyclopenten-1-carbothionic acid anilides 5 and 3-morpholinothiocinnamic acid anilides 8 with 1,2-dibromoethane yield 1-morpholino-cyclopenten-3-aryl-thiazolidine-2-ylidene 7 and 2-(2′-phenyl-2′-oxo-ethylidene-3-aryl)thiazolidine 9 , respectively. Alkylation of 1-indanone- and 1-tetralone-2-carbothionic acid anilides 11 and 12 with dihalogenoalkanes yield 1-oxo-indanylidene- and 1-oxo-tetralidenethiazolidines 14 , 16 and tetrahydro-1,3-thiazines 15 , 17 , respectively.     

Synthese neuer, 3-substituierter 2H-Thiopyran-Derivate via [4+2]-Cycloaddition mittels acceptorsubstituierter Enaminothione

Synthesis of New 3-Substituted 2H-Thiopyran Derivatives via [4+2] Cycloaddition Reactions using Acceptor Substituted Enaminothiones 3- and 4-Nitro acetophenones as well as 3- and 4-trifluoromethyl acetophenones react with POCl₃/DMF (Vilsmeier reagent) to give dimethyliminium perchlorates 1a–d after addition of perchloric acid to the reaction mixture. Substitution of the chloro atom in 1 by using sodium sulfide nonahydrate occurs under mild conditions (in case of nitro compounds at −5°C) leading to enaminothiones 2a–d . Reactions with acroleine and methylvinylketone in refluxing benzene give exclusively 2H-thiopyran derivatives 4a–h , which were isolated in good yields after spontaneous fast elimination of dimethylamine. In contrast, the introduction of 1-nitro-2-phenylethene as the dienophile allows stepwise reaction to give stable adducts 3k and 3l , respectively, and also 3m under mild conditions (reaction at room temperature). ¹H n.m.r. spectroscopic data as well as the elimination of dimethylamine to 4k–m permit the elucidation of the structure of adducts 3k–m .     

Folgeprodukte halogenierter Aldehyde. XVII. Reaktionen des N-(1,2,2,2-Tetrachlorethyl)-trichloracetaldimins mit Alkoholen und Mercaptanen

Derivatives of Halogenated Aldehydes. XVII. Reactions of N-(1,2,2,2-Tetrachloroethyl)trichloroacetaldimine with Alcohols and Thioalcohols Reactions of N-(1,2,2,2-tetrachloroethyl)trichloroacetaldimine 1 with methanol lead to 1,2,2,2-tetrachloroethyl-(2,2,2-trichloro-1-methoxyethyl)amine 2a , N-(2,2,2-trichloro-1-methoxyethyl)trichloroacetaldimine 3a and bis-(2,2,2-trichloro-1-methoxyethyl)amine 5 . After the reaction of the aldimine 1 with ethanol or propanol only the N-(1-alkoxy-2,2,2,-trichloroethyl)trichloroacetaldimines 3b, c are isolated; with thioalcohols only the N-(1-alkylthio-2,2,2-trichloroethyl)-trichloroacetaldimines 4a–c are obtained. The aldimines 3a–c and 4b, c are decomposed on treatment with hydrochloric acid and an excess of an alcohol or thioalcohol to yield the amine hydrochlorides 6a–c, 7b, c , which are transformed into the amines 8a–c and 9b, c . From these amines the derivatives 10–15 are prepared.     

Umsetzungen substituierter 1-Thiochromone und 4(1H)-Chinolone mit Nucleophilen

Reactions of Substituted 1-Thiochromones and 4(1H)-Quinolones with Nucleophiles 1-Thiochromone 1a and 4(1H)-quinolone 1b react with nucleophiles to substitute the methylthio group. Compounds of type 1 are suitable C₃-fragments for the synthesis of novel heterocycles. Hydroxylamine leads to 2-amino-1-thiochromone-3-carboxamide 7 , whereas 1c gives 2-methylthio-1-thiochromone-oxime 8 .     

Reaktionen von zwitterionischen s-Triazolo[4,3-b]pyridazinen mit elektrophilen Reagentien

Reactions of Mesoionic s-Triazolo[4,3-b] pyridazines with Electrophilic Reagents The redox-properties of zwitterionic s-triazolo [4, 3-b]pyridazines 1–3 depend on the heteroatom: products with S-atoms can easily be oxidated. O-Zwitterions 1 and 2 react with diazoniumsalts under azocoupling, while S-zwitterions 3 lead to a dediazonation. The O-zwitterions 1 and 2 can also be bromated, nitrated and hydroxylated electrophilicably. A reaction with dithioliumsalts is not possible. S-Zwitterions 3 react in a more complicated way in the electrophilic reactions mentioned.     

β-Fur-2-yl-α-halogenacrylonitrile. IV. Reaktionen von β-Fur-2-yl-α-halogenacrylonitrilen mit Alkoholen und Phenolen

β-Fur-2-yl-α-halogenacrylonitriles. IV. Reactions of β-Fur-2-yl-α-halogenacrylonitriles with Alcohols and Phenols β-Fur-2-yl-α-halogenacrylonitriles 1a – c react with alcohols and phenols to yield β-fur-2-yl-β-alkoxyacrylonitriles and β-fur-2-yl-β-aroxyacrylonitriles 2a – k respectively. With ethylene glycol α-[2-(fur-2-yl)-1, 3-dioxolan-2-yl]acetonitriles 3a, b are formed.     

Darstellung und Reaktionen von 2-Arylamino-3-nitrochinolinen

Synthesis and Reactions of 2-Arylamino-3-nitroquinolines Condensation of 1-nitro-2,2-bis(methylthio)ethylene with esters of anthranilic acid yields 2-arylamino-3-nitro-4-quinolones. 2 . Analogously, from 1-nitro-2-anilino-2-methylthioethylene and o-aminoketones, 2-anilino-3-nitroquinolines 4 are obtained which can be reduced to 2-anilino-3-amino-quinolines 7 . The latter undergo cyclizations by usual methods to yield substituted triazolo-, imidazolo-, diazepino- and pyrazino-quinolines 9–12 . Reaction of ethyl-2-aminothiophene-3-carboxylates with 1-nitro-2-anilino-2-methylthio-ethylene affords 2-anilino-3-nitrothieno[2,3-b]-4-pyridones 5 .     

Spaltung von 1,2,4-Thiadiazol-3-onen mit Triphenylphosphan: Triphenylphosphonio-thioimidazolate und ihre Folgereaktionen

Fission of 1,2,4-Thiadiazol-3-ones by Triphenylphosphane: gewidinet Triphenylphosphonio Thioimidazolates and Their Consecutive Reactions Treatment of benzimidazo[1,2-d][1,2,4]thiadiazol-3(2H)-ones ( 1 ) and imidazo[1,2-d]-[1,2,4]thiadiazol-3(2H)-ones ( 17 ) with triphenylphosphan leads to the liberation of isocyanate and the formation of triphenylphosphonio-thiobenzimidazolat ( 4 ) and triphenylphosphonio-thioimidazolat ( 18 ), respectively. 2,4-Diphenyl-5-phenylimino-1,2,4-thiadiazol-3-one ( 23 ) is desulfurized with Ph₃P and decomposed into phenyl isocyanate and diphenylcarbodiimide whereas the N-unsubstituted imino-thiadiazol-3-one ( 25 ) is attacked at the exocyclic imino group by Ph₃P to give the N-phosphoranylidene thiourea ( 26 ). The structure of 4 can be rationalized as a dynamic system between polar and apolar valence isomeres. Reactions of 1 and 17 with cyanates, isocyanates, carbon disulfide, acetic anhydride, amines, benzyl chloride, grignard compounds, and CH acidic compounds are described.     

Zur Reaktion von Cyanodithioformiaten mit primären Aminen

Reactions of Cyanodithioformates with Primary Amines N-Alkyldithiooxamides 3 and N,N -dialkyldithiooxamides 4 were synthesized in good yields by reaction of cyanodithioformates 1 with primary aliphatic amines. N-Alkylcyanothioformamides 2 , intermediates in these reactions were obtained in very low yields only. The reaction of 1 and diaminoethane or 1.3-diaminopropane afforded imidazolidine-2-thione 5a respectively perhydropyrimidine-2-thione 5b . The reaction of 1 with 1-chloro-2-aminoethane did gave 2-thiocarbamoylthiazoline 7 .     

Ringöffnungs- und SubstitutionsReaktionen von 4,4-Dihalogen-pyrazolin-5-onen durch Nucleophile

Ring Opening and Substitution Reactions of 4,4-Dihalo-pyrazolin-5-ones with Nucleophiles 1-Aryl-4,4-dihalo-3-methyl-pyrazolin-5-ones ( 1a – c ) undergo ring opening with alkoxides and form alkyl 3-arylazo-2-halo-2-butenoats ( 2a – d ). Analogous reactions take place with ammonia and amines. 4-Nitro-phenoxide reacts with substitution of both halogens to the 4,4-bis(4-nitro-phenyl)-compound ( 5 ). Phenols are selectively orthobrominated by the title compounds 1a and b .     

Zur Molekülverknüpfung mit Schwefelchloriden. X. Bis(arylamino-chloralkyl)-sulfane aus N-β-Methallyl-N-tosyl-anilinen und Schwefeldichlorid

Molecule Linkage by Sulfur Chlorides. X. Bis(arylamino-chloroalkyl)-sulfanes from N-β-Methallyl-N-tosyl-anilines and Sulfur Dichloride Reactions of differently substituted N-β-methallyl-N-tosyl-anilines 1 with sulfur dichloride yield bis(arylamino-chloroalkyl)-sulfanes 2 and 3 and dihydrobenzo-1,4-thiazines 4 . The structural assignment of the products 2 and 3 was carried out by mass spectroscopy and ¹H-n.m.r.-spectroscopy.