Amidinium salts, vinylogous

Cationic dyes with delocalized charge are classified with the methine dyes (see Section 2.6). They may be viewed as vinylogous amidinium salts 3 [1] ... 

Aminocrotonate ester or aminocrotonitriles are cyclocondensed with vinylogous amidinium salts or enaminone ketals to give pyridine-3-carboxylic acid derivatives via electrocyclic ring closure of an intermediate adduct68-70 (equation 50). 

Similarly, Gupton et al. have shown that acyclic amidinium salts (63) and vinylogous amidines (65) are reactive and can be utilized for the synthesis of structurally diverse aldehydes (Scheme 11). 

The reaction of amine hydrochlorides with thioxoesters affords amidinium salts (155 equation 91). Formamidinium salts (156 equation 92) with bulky substituents at the nitrogens can be obtained by oxidation of AA A/ -trisubstituted or AA -disubstitut thioureas with peracetic acid. - Byproducts in this reaction can be ureas and thiourea trioxides. -Dimethylaminoacrolein reacts with dimethylamine hydrochloride to give (157 equation 93), the parent compound of the vinylogous amidinium salt series. - From AA -dimethylthiobenzamide and Al-sulfinyldimethylammonium tetrafluoroborate the benzamidin-ium salt (158 equation 94) was prepared. ... 

Ketene aminals can be transformed by various electrophilic reagents to amidinium salts, thus mineral acids, alkyl halides, A///-dialkyliminium salts, alkoxymethyleneiminium salts, formamidinium salts, acyl halides, diazonium salts, vinylogous amidinium salts,sulfonyl halides, ketene dichlorides ... 

Many vinylogous amidinium salts, e.g. (185) and (186) (Scheme 25), are readily available by double formylation of CHa-acidic or alkenic compounds. Reviews on the chemistry of vinylogous amidinium salts are available. The first azavinylogous foimamidinium salt (187 Scheme 26) was prepared in 1960 by reaction of DMF with cyanuric chloride. The mechanism of this reaction has been estab-lished. Based on these findings new methods for the synthesis of these compounds were developed, e.g. the reaction of isocyanatomethyleneiminium salts with tertiary formamides affords salts (187). In the synthesis of the salts (187) cyanuric chloride can be replaced by phosphorus nitride chloride (PNCl2)3. ... 

Kiesel, M., Haug. E., and Kantlehner, W., Qrthoamidcs. Part 50. Contribution to the chemistry of propionaldehyde aminals. Synthesis and transformalions to push-pull-substituted buta-1,3-dienes, cyclobutanes, vinylogous amidinium salts and 1,2,3-triazoles, J. Prakt. Chem./Chem.-Ztg., 339, 159,... 

Fluoroborates Vinylogous amidinium salts from vinylogous carboxylic acid amides and alkoxyaminomethinium salts... 

Ring closures with vinylogous amidinium salts O... 

Isocyclics s. 25, 581 heterocyclics, also N-condensed, cf. Ang. Ch. 86, 781 (1974) vinylogous amidines and amidinium salts as stabilized push-pull ethylene derivs., review, s. D. Lloyd and H. McNab, Ang. Ch. 88, 496 976)... 

Scheme 1-146. Quinolines by the addition of dilithiated A -BOC-anilines 202 onto "vinylogous" (ethenediylogous) amidinium salts and subsequent acidolysis.

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