2,4‐Dialkylsubstituierte Carbono‐ und Thiocarbonohydrazide, Reaktionen mit Carbonylverbindungen

Abstract

2,4-Dialkylsubstituierte Carbono-und Thiocarbonohydrazide (4) wurden aus Alkylhydrazinen und Phosgen bzw. Thiophosgen hergestellt. Monocarbonylverbindungen reagierten mit 4 (Molverhaltnis l : l) zu Hexahydro-1,2,4,5-tetrazinen (9, 14; Ausnahme 13); im UberschuB ergaben Aldehyde gewdhnlich Dihydrazone (3), Formaldehyd jedoch lieferte 1 ,l'-Methylenbis(hexahydr0-1,2,4,5-tetrazine) (10) sowie die bicyclischen Verbindungen 11 und 12. Die Konstitution von 11 wurde durch Rontgenstrukturanalyse von 11 b gesichert. Dialdehyde und aliphatische bzw. alicyclische a-Diketone reagierten rnit 4 zu doppelten Hexahydro-l,2,4,5-tetrazin-Derivaten (19), arylsubstituierte a-Diketone dagegen lieferten cyclische Dihydrazone (15) undloder Monohexahydro-1,2,4,5-tetrazine (16). 2,4-Dialkyl Substituted Carbono-and Thiocarbonohydrazides, Reactions with Carbonyl Compounds2,4-Dialkyl substituted carbono-and thiocarbonohydrazides (4) were prepared from alkylhydrazines and phosgene or thiophosgene. Mono carbonyl compounds reacted with 4 (molar ratio 1 : 1) to yield hexahydro-I ,2,4,5-tetrazines (9,14; exception 13). Aldehydes in excess generally afforded dihydrazones (3); formaldehyde, however, yielded l,l'-methylenebis(hexahydro-1,2,4,5-tetrazines) (10) as well as the bicyclic compounds 11 and 12. The constitution of 11 was confirmed by X-ray analysis of l l b . Dialdehydes and aliphatic or alicyclic a-diketones reacted with 4 to give double hexahydro-l,2,4$tetrazine derivatives (19), aryl substituted a-diketones on the other hand yielded cyclic dihydrazones (15) and/or mono-hexahydro-I ,2,4,5-tetrazines (16).Bei der Umsetzung von 2,4dialkylsubstituierten Carbono-(4aa, ab) und Thiocarbonohydraziden (4ba, bb) mit Aldehyden im Molverhaltnis 1 : 1 werden Hexahydro-1,2,4,5-tetrazine (9) gebildet, die einen Zugang zu 1,5-Dialkylverdazylen eroffnen1V2). Wir beschreiben hier die Darstellung von 4aa -bb und berichten iiber ihre Reaktionen mit Carbonylverbindungen. A. 2,6Dialkylsubstituierte Carbono-und ThiocarbonohydrazideMono-und 1,5-disubstituierte Carbono-und Thiocarbonohydrazide, fur deren Herstellung es mehrere Verfahren gibt, sind relativ leicht zuganglich 3); fur 2,4-dialkylsubstituierte Derivate trifft dies offenbar nicht zu. 2,4-Dimethylcarbonohydrazid (4aa) -unseres Wissens das bisher einzige Beispiel eines 2,4-Dialkylcarbonohydrazids -wurde aus Methylhydrazin (1 a) und Phosgen in drei Stufen herge~tellt~).

1,5-Dimethyl-1,2,4,5-tetrazinane-3,6-dione

“…Attempted recrystallization of prvH 3 from a mixture of methanol and ethyl acetate led instead to the isolation of colourless needles of (I) that were suitable for X-ray analysis. The compound may have been formed through the 1:1 reaction of methylhydrazine with triphosgene (Neugebauer et al, 1983). A view of the molecular structure of (I), showing the opposite ring puckerings of the two disordered conformers.…”

The Aza Curtius Rearrangement

“…Purification of most products was performed by column chromatography (CC) on 70Ϫ230 mesh 60A silica gel (Aldrich). Ϫ 1 H, 19 General Procedure for the Synthesis of N-Perfluoroalkylsulfonylbenzamides and N-Trifluoromethylsulfonylpivalamide 1a؊g: A solution of acyl chloride (0.03 mol) in anhydrous diethyl ether (30 mL) was added dropwise over 20 min to a stirred mixture of perfluoroalkanesulfonamide (0.03 mol) and triethylamine (6.1 g, 0.08 mol) in anhydrous diethyl ether (100 mL) at 0°C. After stirring for 1 h at room temperature, the reaction mixture was refluxed for 2 h. After cooling, the precipitate was filtered off and washed twice with diethyl ether (20 mL).…”

“…Geometrical parameters of the 6-membered heterocycle in 12 are similar to the corresponding Tablevalues in 1,4-dihydro-1,2,4,5-tetrazine. [19] …”

Verdazyls and Related Radicals Containing the Hydrazyl [R2N‐NR] Group

“…Certain bis(hydrazides) 16 (R = methyl, CH 2 Ph) were later found to be accessible directly from the monoalkylhydrazines (eliminating the need to prepare the hydrazone 14 and subsequent NH 2 deprotection of bis-benzylidene intermediate 15) either by performing the reaction at low temperatures 43 and/or by using triphosgene (bis(trichloromethyl)carbonate) as a phosgene alternative (Scheme 7.6). 44 Neugebauer has made 6-thioxoverdazyls 8 by using thiophosgene in place of phosgene (Scheme 7.7).…”

“…44 Neugebauer has made 6-thioxoverdazyls 8 by using thiophosgene in place of phosgene (Scheme 7.7). 43 Thus, dehydrogenation of the 6-thioxotetrazanes 18 gives 6-thioxoverdazyls 8. 42 An additional feature of the thioxotetrazanes 18 consists of their desulfurization to the corresponding tetrazanes 19 with a saturated carbon at C6.…”