Das von W . Strinkopf beobachtete thermische Zerfallsprodukt von Dichlordioxim (1) wird als Dicyan-di-N-oxyd (2) erkannt, unter dessen mesomeren Formen 2b iiberwiegt. Krist. monomeres 2 ist bei -78" weitgehend haltbar, zersetzt sich bei -45" i. Vak. plotzlich ohne Explosion unter Aussendung weiBen Lichtes, detoniert bei Raumtemperatur und polymerisiert in Losung zum Polyfuroxan 8. Die Dampfe von 2 reizen die Atmungsorgane. 2 laRt sich gravimetrisch als Dibromdioxim und titrimetrisch nach Reaktion rnit Triphenylphosphin als Dicyan bestimmen. -Halogenwasserstoffsauren (auRer Fluorwasserstoff) werden von 2 elektro-phi1 zu den Dihalogendioximen addiert. Mit je 2 Molaquivv. NaOH, Ba(0H)z und Cu(1I)acetat entstehen die entsprechenden Salze von aci-Nitro-acethydroxamsaure (13) ; Reaktion von 2 mit Alkoxyl-Ionen fiihrt zu den Estern von 13. Mit Ammoniak entsteht a m 2 Oxalyldiamid-dioxim (14); rnit Anilin, Cyclohexylamin und Diathylamin bilden sich in nucleophiler Reaktion substituierte Amidoxime (15-17). 1.2-Diamine reagieren rnit 2 zu 1.4-Diazinen (18, 19) ; tertiare Amine liefern unbestandige innere Salze trisubstit. Amidoxime (z. B. 20a), die sich in einigen Fallen als Halogenide quartarer Oxaldiamidinium-dioxime (20 b) fassen lassen und die auch aus den tert. Aminen und 1 entstehen. Phenylhydrazin reduziert 2 teils zu Dicyan, teils wird es zu Oxalyl-bis-phenylhydrazid-dioxim (22a) addiert, das RingschluR zu 22 b erleidet. Mit Sulfid-Ionen reagiert 2 zu Dithio-oxaldihydroxamsaure (23) und Tetraoximino-1.4-dithian (24), mit Cyanid-Ionen zu Dicyandioxim (26). Mit khylenen bzw. Acetylenen geht 2 1.3-dipolare Additionen zu cis-und trans-3.3'-Bi-A2-isoxazolinylen (z. B. 34a und 34b) bzw. zu 3.3'-Bi-isoxazolylen (29-31) ein, welch leztere zu Furoxanen (28, 32) weiterreagieren. Entsprechende Ringschlusse werden bei der Reaktion von 2 rnit Dienen (z. B. zu 37-39) beobachtet. Darstellung und EigenschaftenIm Jahre 191 1 haben Steinkopj und Jiirgens4) beobachtet, daB sich Dichlorglyoxim (Dichlordioxim, Oxaldihydroxamsiure-dichlorid, 1) beim Behandeln mit NazC03-*) Herrn Prof. Dr. Karl Freudenberg zum 80. Geburtstag gewidmet. 1 ) 3. Mitteilung: C. Grundmann und H.-D. Frommeld, J. org. Chemistry 30, 2077 (1965). 2) Auszugsweise vorgetragen im Chemischen Kolloquium der Institute fur Organische Che-3) Vorlaufige Mitt. : C . Grundmann, Angew. Chem. 75, 450 (1963). 4) W. Steinkopf und B. Jiirgens, J. prakt. Chem. [2] 83, 453 (191 I), und zwar S. 460. mie der Universitaten Heidelberg und Miinchen am 25. bzw. 26. Marz 1963. C . Grundmann, V. Mini, J. M . Dean und H.-D. Frommeld Bd. 687Losung oder bei starkem Erhitzen unter Entwicklung eines intensiv Nitriloxyd-artigen Geruches zersetzt.Die Angaben iiber die Alkali-Empfindlichkeit von 1 sind nicht ohne Widerspruch: Steinkopfund Jiirgenss) bemerkten, daR nach dem Behandeln von 1 mit 2 Moll. NaOH unverandertes Ausgangsmaterial wiedergewonnen wurde, woraus sie auf die (alkalistabile) anti-Konfiguration von 1 schlossen. Ungnade und Mitarbeiters) iibernahmen diese Angabe und nahmen das UV-Sp...
Several s-triazine mono-and bisaldoximes were obtained readily and in fair yields by the base-catalyzed condensation of the corresponding methyl-s-triazines with alkyl nitrites. Hydrolysis of the oximes to the s-triazine aldehydes was only possible with 4,6-diaryl-s-triazine aldoximes. These aldehydes also could be prepared directly from the 2-methyl-4,6-diary 1-s-triazines by reaction with nitrous acid in concentrated sulfuric acid.During the course of our investigation of novel nitrile oxides,2 we became interested in the preparation of mono-and difunctional s-triazine aldoximes as intermediates. Since the only known route to s-triazine aldehydes is limited to monoaldehydes with a narrow choice of possible substituents in the 4-and 6-position,3 we tried to convert the readily accessible methyl-striazines (I) into the corresponding aldehydes or aldoximes.Attempted oxidation of the methyl to the formyl group in 2-methyl-4,6-diphenyl-s-triazine (Id) by means of selenium dioxide, chromium trioxide, or chromyl chloride failed, as well as the ozonization of the 2,4,6tristyryl-s-triazine (II).4 In all experiments excessive cleavage of the s-triazine ring occurred prior to or simultaneously with the oxidation of the methyl group. The Ortoleva-King reaction which has been useful in analogous cases5 proceeded with trimethyl-s-triazine only to the bisquaternary perchlorate (III). Ill resisted all efforts to convert it into the corresponding bisnitrone.Ostrogovich, et al.,6 transformed 2-methyl-4,6-dihydroxy-s-triazine (Ig) into the 4,6-dihydroxy-s-triazine-2-formaldoxime (Vllh) by reaction with dinitrogen trioxide in water; similarly they obtained from 2benzyl-4,6-dihydroxy-s-triazine with nitrosyl chloride (generated in situ from ethyl nitrite and hydrochloric acid in acetic acid) the 4,6-dihydroxy-s-triazinyl-2phenyl ketoxime (IX). We have convinced ourselves that these methods are not applicable to any of the triazines (la to If) used in this study.We found then that s-triazines having at least one methyl group in the 2-position can be transformed readily and with fair to good yields into the corresponding s-triazine aldoximes (VII) by condensation with an alkyl nitrite in the presence of an alkali metal alkoxide. If the starting material contains methyl groups in the 2-and 4-positions, s-triazine 2,4-bisaldoximes are formed as the main product. Under milder conditions, however, substantial amounts of the monoaldoxime can be obtained usually. Trimethyl-s-triazine (la) yields, even under the strongest possible conditions, only the 6-methyl-s-triazine 2,4-bisaldoxime (Vllb). We have been unable to convert Vllb further into the s-triazine trisaldoxime (Vile).7
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
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