Beilstein J. Org. Chem.2017,13, 579–588, doi:10.3762/bjoc.13.57
hydrogenation of an N-benzyl derivative. Crystal structure analyses of a 4-benzylamino-1,2,4-triazolium-3-hydrazinide and of two derived 1,2,4-triazolium salts are presented.
Keywords: guanidines; mesoionic compounds; triaminoguanidiniumsalts; 1,2,4-triazolium-3-aminides; Introduction
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, triaminoguanidiniumsalts or the neutral triaminoguanidine have been reacted with carbonyl compounds. Reactions with aldehydes [3][4][5][6][7] or ketones [8][9][10] yielded the corresponding tris(iminyl)guanidines; cyclocondensation of pentane-2,4-dione at one hydrazinyl branch of TAG-Cl afforded a pyrazole which
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Graphical Abstract
Scheme 1:
Reactions of aminoguanidines with carboxylic acids and acid chlorides. The structural formulae show...
Beilstein J. Org. Chem.2014,10, 2255–2262, doi:10.3762/bjoc.10.234
triaminoguanidiniumsalts underwent a threefold carbamoylation with aryl isocyanates to furnish 1,2,3-tris(ureido)guanidinium salts, while p-toluenesulfonyl isocyanate led only to a mono-ureido guanidinium salt. With aryl isothiocyanates, 3-hydrazino-1H-1,2,4-triazole-5(4H)-thione derivatives were obtained. Compounds
(arylideneamino)- and tris(alkylideneamino)guanidinium salts [7][8][9]; these were the first examples of a threefold symmetrical functionalization of the triaminoguanidinium ion. On the other hand, reactions of triaminoguanidiniumsalts with carboxylic acids generated 4-amino-3-hydrazinyl-1,2,4-triazoles [10][11
1,2,3-triazidoguanidinium salt [16][17].
Direct N-alkylation reactions of the triaminoguanidinium ion are not known. Triaminoguanidiniumsalts are soluble only in water or in hot alcohol/water mixtures, but not in the common organic solvents, which prevents the use of alkylating reagents such as alkyl
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Graphical Abstract
Scheme 1:
Conditions: a) benzaldehyde, ethanol/water, reflux, 1 h, 96% yield; b) H2, Pd/C (10%), MeOH, rt, 48...