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Copyright of Zeitschrift für Naturforschung B: A Journal of Chemical Sciences is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article describes various chemical reactions in which orthoamides are reacted with other compounds. New compounds are synthesized, such as vinylogous guanidinium bromides and vinylogous guanidinium tetraphenylborates. Ketenimines are also synthesized from orthoamides and phosphonic acid esters. The structure of the ketenimines is described by polar resonance structures. Information is also provided on the yields and properties of the resulting compounds. Further investigations into the reactions and the resulting compounds are encouraged. [Extracted from the article]

Copyright of Zeitschrift für Naturforschung B: A Journal of Chemical Sciences is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The 1,1-bis(dimethylamino)-1,3-butadienes (keten aminals) 11a–l are prepared from orthoamide derivatives of alkyne carbonxylic acids 9b, d, e, i and CH2-acidic compounds 10a–c, f–h, k, o. The C-silylated orthoamide derivative 9c shows an ambivalent behaviour towards CH-acidic compounds. Reactions of 9c with strong CH2-acidic compounds like the nitro alkanes 10m, n and strongly enolized carbonyl compounds as methyl acetoacetate, cyanoacetamide, dibenzoylmethane, 1,3-dimethylbarbituric acid proceed under desilylation to give the ketene aminals 11u–z. In contrast to these reactions, the C-silylated ketene aminals 11o–t are obtained from 9c and weaker CH2-acidic compounds as dimethyl malonate, cyanoacetic acid derivatives and benzylcyanides. CH2/NH2-acidic compounds [cyanoacetamide (10d) and N-ethyl-cyanoacetamide (10f)] react with the orthoamide derivatives 9b, e–g at the acidic carbon-hydrogen bond to give the ketene aminals 11ac, ad, af, ag, ai, which cyclize to the pyridones 14a–d, d–g on heating. From the reaction of the orthoamide 9d with cyanoacetamide the pyridone 14c results directly. The persubstituted pyridone derivative 19 is formed by the reaction of cyanoacetamide with a mixture of the isomeric orthoamides 15 and 16. The 5,5-diamino-2,4-pentadienamide 11v attacks the orthoamide 9a at C3/C1. In the product 20 a cross conjugated multiple bond system is formed which contains an 1-aza-2,3-diamino function and a further ketene aminal function. [ABSTRACT FROM AUTHOR]

The preparation of the vinylogue guanidinium salt 10c is described. The reaction of the vinylogue orthocarbonic acid amide derivative 12 with CH2-acidic compounds 14a–s affords the ketene aminals 15a–s. At room temperature the succinimide 19a is deprotonated by 12 to give the vinylogue salt 10e. The bis-ketene aminal 20 is formed in the reaction of 19a with 12 at elevated temperatures. Succinic acid esters 21 do not react cleanly with the orthoamide 12, but mixtures of ketene aminals 23 and bis-ketene aminals 22 are formed. From succinodinitrile (24) and 12 the bis-ketene aminal 25 could be obtained, which is also accessible by the action of the salt 10c with 24 in the presence of sodium hydride. [ABSTRACT FROM AUTHOR]

The preparation of the vinylogue guanidinium salt 10c is described. The reaction of the vinylogue orthocarbonic acid amide derivative 12 with CH2-acidic compounds 14a–s affords the ketene aminals 15a–s. At room temperature the succinimide 19a is deprotonated by 12 to give the vinylogue salt 10e. The bis-ketene aminal 20 is formed in the reaction of 19a with 12 at elevated temperatures. Succinic acid esters 21 do not react cleanly with the orthoamide 12, but mixtures of ketene aminals 23 and bis-ketene aminals 22 are formed. From succinodinitrile (24) and 12 the bis-ketene aminal 25 could be obtained, which is also accessible by the action of the salt 10c with 24 in the presence of sodium hydride. [ABSTRACT FROM AUTHOR]