Radikalische Cyclisierungen von Alkenyl-substituierten 4,5-Dihydro-1,3-thiazol-5-thiolen

Radical Cyclizations of Alkenyl-Substituted 4,5-Dihydro-1,3-thiazole-5-thiols Heating of 5-alkenyl- or 5-alkinyl-4,5-dihydro-1,3-thiazole-5-thiols of type 5 in the presence of a radical initiator gave dithiaspirobicycles in fair-to-excellent yield (Scheme 3). Under analogous conditions, the 4,5-dihydro-4-vinyl-1,3-thiazole-5-thiol 5d underwent a cyclization to give the annellated dithiabicycle 7 (Scheme 4). In this reaction, a minor product 8 was formed by an unknown reaction mechanism. The structure of 8 was established by X-ray crystallography. The starting 1,3-thiazole-5-thiols 5 have been synthesized by carbophilic alkylation of me C?S group of 1,3-thiazole-5(4H)-thiones with Grignard-reagents or alkylcuprates. The thiazolethiones were obtained by the reaction of 3-amino-2H-azirines with thiobenzoic acid followed by sulfurization and cyclization. The 4-benzyl derivative 1b was thermally rearranged via 1,3-benzyl migration to yield the benzyl (1,3-thiazol-5-yl) sulfide 11 (Scheme 5).     

Synthese von 1,3-Dimethylpyrazol-4,5-dion

Ohne ZusammenfassungTeilauszug aus der DissertationP. Gröbner, Universität Innsbruck (1970).     

Über die Synthese von 1,3-Dihydro-2,1,4-benzothiadiazepinen

Zusammenfassung Das Dinatriumsalz des 5-Chlor-2-(chlormethansulfonamido)-benzophenon--oxims (2) liefert beim Erhitzen 7-Chlor-5-phenyl-1,3-dihydro-2,1,4-benzothiadiazepin-2,2,4-trioxid (3). Es wurden die Strukturen von3 sowie weiterer Derivate dieses neuen Ringsystems bewiesen und Abbauprodukte aufgeklärt, die aus diesen Verbindungen beim Einwirken von Säuren, beim Bestrahlen mit UV-Licht oder beim Erhitzen entstehen.

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Syntheses of 1,3-dihydro-2,1,4-benzothiadiazepines

Heating the disodium salt of 5-chloro-2-(chloromethane-sulfonamido)-benzophenone--oxime (2) yields 7-chloro-5-phenyl-1.3-dihydro-2.1.4-benzothiadiazepine-2.2.4-trioxide (3). The structures of3 and of further derivatives of this new ringsystem were determined and degradation products, which are formed from these compounds by treatment with acids, by UV-irradiation or by heating were identified.

     

Synthese und Hydrolyse von 1,3-Dihydro-1,3,2-benzodiazaphosphol-2-oxiden

Zusammenfassung Verschiedene 1,3-Dihydro-1,3,2-benzodiazaphosphol-2-oxide und entsprechende Bisverbindungen wurden hergestellt. Einige der Verbindungen konnten nur ohne Lösungsmittel bei Temperaturen bis zu 250°C in guter Ausbeute und in großer Reinheit erhalten werden.Bei der Hydrolyse werden meist beide P–N-Bindungen gespalten, und es entsteht das Monosalz der Phosphonsäure mit dem Diamin; dieses Salz ist identisch mit dem aus den beiden Komponenten direkt erhaltenen.

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Various 1.3-dihydro-1.3.2-benzodiazaphosphole-2-oxides and the corresponding bis phosphole oxides have been prepared. Some of the compounds allowed to be prepared in satisfactory yield and high purity only in the absence of solvents at temperatures up to 250°C.Hydrolysis usually entailed cleavage of the two P–N-bonds, and interaction with the diamine yields the monosalt of phosphonic acid; this salt is identical with that obtained by direct interaction of the two reactants.

     

Über die Synthese von substituierten 1,3-Dihydro-5-(2-pyridyl)-thieno[2,3—e]-1,4-diazepin-2-onen

The preparation of the title substances as well as their chlorination in position 7 and methylation in position 1 are described.     

Über die Synthese von 1,3-Dihydro-3-(2-dimethylaminoäthyl)-1-(3-thienyl)-benzimidazol-2-onen

The synthesis of 1-(3-thienyl)-benzimidazol-2-ones (3 a and4), described in an earlier paper¹, has been further investigated. The Na-salt of3 a is converted to a benzimidazolone substituted in position 3 (3 b). Dehydrogenation of the thiophene nucleus of3 a with chloranil yields5 a, which undergoes substitution in position 3 with Cl(CH₂)₂N(CH₃)₂ to give5 b. Monochlorination of5 a yields5 c, the structure of which is confirmed by¹H-NMR-spectroscopy.5 d is obtained by reaction of the Na-salt of5 c with Cl(CH₂)₂N(CH₃)₂.      

Synthese von 4-Benzylthio- und 4-(Arylthio)-1,3-oxazol-5(2H)-onen

Synthesis of 4-(Benzylthio)-and 4-(Arylthio)-1,3-oxazole-5(2H)-ones Following a known procedure, 4-(benzylthio)-1,3-oxazol-5(2H)-one ( 4a ) was synthesized starting from sodium cyanodithioformate ( 1 ) and cyclohexanone (Scheme 1). The structure of the intermediate 4-(benzylthio)-1,3-thiazol-5(2H)-one ( 3a ) was established by X-ray crystallography. An alternative route was developed for the synthesis of 4-(arylthio)-1,3-oxazol-5(2H)-ones which are not accessible by the former reaction. Treatment of ethyl cyanoformate ( 5 ) with a thiophenol in the presence of catalytic amounts of Et₂NH and TiCl₄, followed by addition of a ketone and BF₃.Et₂O in a one-pot-reaction, gave 4f–i in low-to-fair yields (Scheme 3). Both synthetic pathways-complementary as for benzyl–S and aryl-S derivatives–seem to be limited with respect to variation of substituents of the ketone.     

Synthese von 4(5)-acyl-5(4)-alkylimidazolen aus symmetrischen 1,3-dicarbonylverbindungen

Synthesis of 4(5)-Acyl-5(4)-alkylimidazoles from Symmetrical 1,3-Diones A new synthesis of 4(5)-acyl-5(4)-alkylimidazoles 1 is described. The symmetrical 1,3-diones 5a and 5b were reacted with N₂O₄ to give the nitro compounds 7a and 7b , respectively; 5c was treated with NaNO₂ to give the nitroso compound 7c (Scheme 2). Hydrogenation of 7a , 7b and 7c over Pd/C in acetic acid/acetic formic anhydride yielded the formamides 9a , 9b and 9c , whose cyclization in formamide/formic acid afforded the 4(5)-acyl-5(4)-alkylimidazoles 1a, 1b and 1c , respectively. Oxazoles 11a and 11b were obtained from the corresponding formamides 9a and 9b with methanesulfonic acid/P₂O₅.     

Synthese von 4,4-disubstituierten 1,3-Thiazol-5(4H)-thionen

Synthesis of 4,4-Disubstituted 1,3-Thiazol-5(4H)-thiones An easy synthesis for the 1,3-thiazol-5(4H)-thiones 5 , a class of heterocycles which have hitherto only been available with difficulty, is described. Reaction of 3-amino-2H-azirines 25 with thiocarboxylic acids at 0° yields monothiodiamides of type 20 (Scheme 6) which, on treatment with Lawesson reagent at 100°, undergo thiation and cyclization to give 5 in good yield.     

Ortho-Formylierung von Anilinen durch Umlagerung von Bis(methylthio)methan-S-(N-aryl)imiden

By reaction of anilines with dithioacetals of formaldehyde [in particular, with bis(methylthio)methane] andtert. butylhypochlorite the corresponding intermediate mono-sulfimides are formed which rearrange easily—after addition of triethylamine—to yield dithioacetals5 ofo-amino benzaldehydes.

Herrn emer. o. Univ. Prof. Dr.O. Hromatka zum 80. Geburtstag gewidmet.     

Synthesis of new 1,3-thiazole derivatives from 2(5)-hydroxyalkyl-1,3-thiazole-5(2)-carbaldehydes

Reactions of substituted 2-hydroxyalkyl-1,3-thiazole-5-carbaldehydes and 5-hydroxyalkyl-1,3-thiazole-2-carbaldehydes with phenylhydrazine, isoniazid, N-substituted rhodanines were performed as well as Biginelli reaction with acetoacetic ester and urea. As a result, new 1,3-thiazole derivatives were obtained. They are of interest as potential bioactive substances.     

Die Synthese von 1,3-Bis(dichlorcarbo)-2,4-bis(dihalogen)cyclo-diborazanen

Zusammenfassung 1,3-Bis(dichlorcarbo)-2,4-bis(dihalogen)cyclodiborazane wurden durch Umsetzung von Rhodantrichlorid mit Trihalogenboranen dargestellt. Die Massenspektren und IR-Spektren bestätigen die Struktur der Verbindung, für welche die Punktgruppe D_2h angenommen wird.

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From the reaction of thiocyanogen trichloride with trihaloboranes 1,3-bis(dichlorcarbo)-2,4-bis(dihalogeno)cyclodiborazanes have been obtained. IR and mass spectra confirm the structure of these compounds, for which a D_2h symmetry is proposed.

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