Bestimmung der Summe der Verunreinigungen in Lösungsmitteln, die durch gerichtetes Erstarren gereinigt wurden
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Die Umsetzung der Trihalogenide 7a, b mit Natriumcyanid in Dimethylformamid ergab das Cyclopropandicarbonitril9 anstelle des Trinitrils 7c, das als Vorstufe von 2,4,9-Triazaadamantanen dienen sollte. Die Photolyse und Thermolyse des bemerkenswert stabilen Triazids 13c verliefen unubersichtlich durch Bildung nicht identifizierbarer Produkte, unter denen das Triazaadamantan 6a oder Hydrolyseprodukte des Triimins 14 nicht aufzufinden waren. Das leicht cyclisierende Triketon 31 wurde aus dem Trisaurechlorid 3 k mit iiberschussigem Lithiumdimethylcuprat nach schonender Aufarbeitung erhalten und erwies sich als Schlusselverbindung fur neue Heteraadamantane: Methanolat bewirkte intramolekulare Aldoladdition und Cyclisierung von 31 zum 2,4-Dioxaadamantan 15. Uberschussiges flussiges Ammoniak uberfuhrte 31 fast quantitativ in das 2,4-Dioxa-9-azaadamantan 16a. Das gleiche Ringsystem (16b) wurde aus 31 und 12 mol Hydrazinhydrat gebildet. Dagegen erhielt man aus 31 mit einem sehr hohen UberschuR Hydrazinhydrat das 2-0xa-4,9-diazaadamantan 16c. Wasserfreies Hydrazin in trockenem Ethanol und 31 ergaben schlieRlich das 2,4,9-Triazaadamantan 16d. Die Strukturen der neuen Verbindungen wurden IR-und NMR-spektroskopisch gesichert. Laut LAOCOON-111-Analyse kommen die komplexen 'H-NMR-Multipletts der Methylenprotonen von 15 und 16a -c nur durch W-Kopplungen von 2 -3 Hz und geminale Kopplungen zustande.2,4-Dioxa-, 2,4,9-Trioxa-, 2,4-Dioxa-9-aza-, 2-0xa-4,9-diaza-, and 2,4,9-Triazaadamantanes l)The reaction of the trihalides 7a, b with sodium cyanide in dimethylformamide afforded the cyclopropanedicarbonitrile 9 instead of the tricarbonitrile 7c which had been designed as a precursor to 2,4,9-triazaadamantanes. Both the photolysis and thermolysis of the remarkably stable triazide 13c proceeded in an ill-defined way, producing unidentifiable products among which neither the triazaadarnantane 6a nor hydrolysis products of the triimine 14 could be detected. The readily cyclizing triketone 31 was obtained from the reaction of the tricarbonyl chloride 3k with an excess of lithium dimethylcuprate followed by careful work-up. It proved to be the key to several novel heteraadamantanes: Thus, methoxide brought about an intramolecular aldol addition and cyclization of 31 to the 2,4-dioxaadamantane 15. An excess of liquid ammonia converted 31 into the 2,4-dioxa-9-azaadamantane 16a almost quantitatively. The same ring system (16b) was formed in the reaction of 31 with 12 mol of hydrazine hydrate. In contrast, the reaction of 31 with a very large excess of hydrazine hydrate afforded the 2-oxa-4,9-diazaadamantane 16c. Finally, 31 reacted with dry hydrazine in ethanol to yield the 2,4,9-triazaadamantane 16d. The structures of the new compounds were established by IR and NMR spectroscopy. Analysis of the complex 'H NMR multiplets of the methylene protons of 15 and 16a -c by LAOCOON 111 shows that they arise exclusively from W-couplings of 2 -3 Hz and geminal couplings.
Die Umsetzung der Trihalogenide 7a, b mit Natriumcyanid in Dimethylformamid ergab das Cyclopropandicarbonitril9 anstelle des Trinitrils 7c, das als Vorstufe von 2,4,9-Triazaadamantanen dienen sollte. Die Photolyse und Thermolyse des bemerkenswert stabilen Triazids 13c verliefen unubersichtlich durch Bildung nicht identifizierbarer Produkte, unter denen das Triazaadamantan 6a oder Hydrolyseprodukte des Triimins 14 nicht aufzufinden waren. Das leicht cyclisierende Triketon 31 wurde aus dem Trisaurechlorid 3 k mit iiberschussigem Lithiumdimethylcuprat nach schonender Aufarbeitung erhalten und erwies sich als Schlusselverbindung fur neue Heteraadamantane: Methanolat bewirkte intramolekulare Aldoladdition und Cyclisierung von 31 zum 2,4-Dioxaadamantan 15. Uberschussiges flussiges Ammoniak uberfuhrte 31 fast quantitativ in das 2,4-Dioxa-9-azaadamantan 16a. Das gleiche Ringsystem (16b) wurde aus 31 und 12 mol Hydrazinhydrat gebildet. Dagegen erhielt man aus 31 mit einem sehr hohen UberschuR Hydrazinhydrat das 2-0xa-4,9-diazaadamantan 16c. Wasserfreies Hydrazin in trockenem Ethanol und 31 ergaben schlieRlich das 2,4,9-Triazaadamantan 16d. Die Strukturen der neuen Verbindungen wurden IR-und NMR-spektroskopisch gesichert. Laut LAOCOON-111-Analyse kommen die komplexen 'H-NMR-Multipletts der Methylenprotonen von 15 und 16a -c nur durch W-Kopplungen von 2 -3 Hz und geminale Kopplungen zustande.2,4-Dioxa-, 2,4,9-Trioxa-, 2,4-Dioxa-9-aza-, 2-0xa-4,9-diaza-, and 2,4,9-Triazaadamantanes l)The reaction of the trihalides 7a, b with sodium cyanide in dimethylformamide afforded the cyclopropanedicarbonitrile 9 instead of the tricarbonitrile 7c which had been designed as a precursor to 2,4,9-triazaadamantanes. Both the photolysis and thermolysis of the remarkably stable triazide 13c proceeded in an ill-defined way, producing unidentifiable products among which neither the triazaadarnantane 6a nor hydrolysis products of the triimine 14 could be detected. The readily cyclizing triketone 31 was obtained from the reaction of the tricarbonyl chloride 3k with an excess of lithium dimethylcuprate followed by careful work-up. It proved to be the key to several novel heteraadamantanes: Thus, methoxide brought about an intramolecular aldol addition and cyclization of 31 to the 2,4-dioxaadamantane 15. An excess of liquid ammonia converted 31 into the 2,4-dioxa-9-azaadamantane 16a almost quantitatively. The same ring system (16b) was formed in the reaction of 31 with 12 mol of hydrazine hydrate. In contrast, the reaction of 31 with a very large excess of hydrazine hydrate afforded the 2-oxa-4,9-diazaadamantane 16c. Finally, 31 reacted with dry hydrazine in ethanol to yield the 2,4,9-triazaadamantane 16d. The structures of the new compounds were established by IR and NMR spectroscopy. Analysis of the complex 'H NMR multiplets of the methylene protons of 15 and 16a -c by LAOCOON 111 shows that they arise exclusively from W-couplings of 2 -3 Hz and geminal couplings.
RI-R2-H -(CH2)2-Me -(CH2)2-3b, 4b Me -(CH2)3-H -MqC-C&-CMq-H -(CH2)3-H -(CH&-Lithiation of the annulated tetrazoles 6a, c with butyllithium yields the N-lithiotetrazoles 7a, c which are allowed to react with alkyl halides. Alkylation at the a-carbon atom is observed in the reaction with methyl iodide (+ 6b, d), l-bromo-2chloroethane (7c + 14a), and 1,3-dibromopropane (+ 16, 17), while 1,2-dichloro-and 1,2-dibromoethane give other products, viz. 11 -13. Quaternisation of 6 with dimethyl sulphate affords mixtures of 1-methyl-(1) and 2-methyltetrazolium salts (8) (3:l-4:l) from which the hexafluorophosphates 1 .PF6 are obtained by crystallisation. Methyl triflate converts the a-azidonitriles 9 into the N-methylnitrilium triflates 10 which immediately undergo an intramolecular 1,3-dipolar cycloaddition to afford the 1-methyltetrazolium triflates 1 . F3CS03. Cyclisation of 16 by intramolecular N-alkylation furnishes the bisannulated tetrazolium bromide 3a . Br. Attempts to obtain the lower homologue 15, either from 14a or from 17, met with failure. Instead, 17 rearranges via 15b into 14b. The a-branched tetrazole 24 is synthesised from ethyl cyanoacetate and the bromide 18. Double cyclisation of 24 affords the bisannulated tetrazolium chloride 3b . C1. The analogous scheme, envisaged for the synthesis of the lower homologue 32, failed in the last step owing to the high strain of this system. Deprotonation of 1,4-substituted 5-alkyltetrazolium salts affords 5-alkylidenedihydrotetra~oles[~~~] which undergo a number of interesting reactions. Photoextrusion of molecular nitrogen yields diastereoselectively iminoaziridines in the E configuration[*]. Iminoaziridines are also formed on thermolysis, besides products derived from cycloadducts of fragments like methyl azide or 1,3-diazabutadienes to the exocyclic double bond of 5-alkylidenedihydrotetrazole~[~]. This double bond is extremely electron-rich and polari~ed[~] and hence even adds normally unreactive 1,3-dipoles such as alkyl azidesL6]. Electrophilic azides afford zwitterions, that are intermediates of non-concerted 1,3-dipolar cycloaddition reactions['], or 5-imino-l,4,5,6-tetrahydro-l,2,3,4tetrazines via [3 + 21 cycloaddition followed by extrusion of molecular nitrogen with concomitant ring expansion[*]. With the view of exploiting and extending the rich chemistry of 5-alkylidenedihydrotetrazoles, we embarked on the synthesis of a number of annulated tetrazolium salts of type 1 and 3 which yield the annulated alkylidenedihydrotetrazoles 2 and 4, respectively, on deprotonation[']. Three different routes were envisaged: Alkylation of known annulated tetrazoles, cyclisation by intramolecular N-alkylation, and intramolecular [3 + 21 cycloaddition of o-azidonitrilium salts. The results are reported here. . . N=N X-N=N 1 2 3 2 6 H 7 R -7 G Q 4 R a R \ I N=N \ I N=N X-2 1 3 4Annulated Tetrazoles f114,1s1) and hydrogenation of tetrazolo[ 1,5-a]pyridine The annulated tetrazoles 6a, c, and f, which were needed ( 6~' '~~) .The tetramethyl compound 6e was now obtained as starti...
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