Mutual effect of the N-amino group and the heteroring in N-aminobenzazoles

Пожарский, А. Ф.; Кузьменко, В. В.; Bumber, A. A.; Петров, Е. С.; Terekhova, M. I.; Chikina, N. L.; Nanavyan, I. M.

doi:10.1007/bf00479913

Cited by 11 publications

(9 citation statements)

References 5 publications

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“…1-Aminobenzimidazole ( 2 ) was synthesized from benzimidazole ( 1 ) and hydroxylamine- O -sulfonic acid in 75% yield following a literature procedure (Scheme , Table ), Quaternization of N -(arylmethyleneimino)benzimidazoles 4a − f with butyl iodide 5 gave the corresponding 3-butyl- N -(arylmethyleneimino)benzimidazolium iodides 6a − f in quantitative yields (Scheme , Table ).…”

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confidence: 99%

Carbene-Mediated Transformations of 1-(Benzylideneamino)benzimidazoles

et al. 2011

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Carbene-mediated transformations of N-(3-butylbenzimidazol-3-ium-1-yl)-1-arylmethanimine iodides with carbon disulfide and benzoyl isothiocyanate gave the corresponding NHC·CS(2) betaines in 68-85% and benzoyl-[1-butyl-3-[(E)-(aryl)methyleneamino]benzimidazol-1-ium-2-carbothioyl]azanides, respectively, in 74-85% yields. However, reaction with excess isopropyl isothiocyanate in NaH/THF at room temperature yielded the 1-butyl-1',3'-diisopropyl-3-[(E)-(aryl)methyleneamino]spiro[benzimidazole-2,5'-imidazolidine]-2',4'-dithiones (74-77%).

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confidence: 99%

Carbene-Mediated Transformations of 1-(Benzylideneamino)benzimidazoles

et al. 2011

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“…[20] The subsequent amination of benzimidazole 1 with the sodium salt of hydroxylamine-O-sulfonic acid (HASA) formed the key NÀ N bond, but it was necessary to cool the reaction mixture constantly below 10 °C during the addition of the reagents in comparison to reported protocols. [21,22] The conversion of 1 b was about 75 %, even when a large excess of the reagent was used. Compound 2 b was easily separated from the starting material 1 b by crystallization as a potassium salt at first, which was insoluble in water.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Unsymmetrical 1,1’‐Bibenzimidazoles via an N‐Amination Reaction Forming the Key N‐N Bond

Toman

Cankař

2022

ChemistrySelect

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The novel synthesis of unsymmetrical 1,1’‐bibenzimidazoles is described. The key N−N bond was introduced on 1H‐benzimidazole or 1H‐benzimidazole‐2‐sulfonic acid by N‐amination with hydroxylamine‐O‐sulfonic acid (HASA). The precursors, 1‐[(2‐nitrophenyl)amino]‐1H‐benzimidazoles, were prepared by nucleophilic aromatic substitution of 1‐fluoro‐2‐nitrobenzene with 1H‐benzimidazole‐1‐amines. The synthesis was demonstrated on 11 novel 1,1’‐bibenzimidazoles, which were prepared in the final step by one‐pot reduction/cyclization with DMF or DMA acetals under mild acidic conditions in good overall yields.

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“…[475] Such amino groups can be alkylated and acylated by way of their anions, [30] and they are subject to the usual reactions with carbonyl compounds, [158,476±478] especially as the quaternary salts (but there is often accompanying ring cleavage). [475] Such amino groups can be alkylated and acylated by way of their anions, [30] and they are subject to the usual reactions with carbonyl compounds, [158,476±478] especially as the quaternary salts (but there is often accompanying ring cleavage).…”

Section: Methods 4: Amino Groupsmentioning

confidence: 99%

“…Benzimidazol-2-amines, however, exist almost exclusively in the amino rather than imino form, with spectroscopic, dipole moment, and X-ray studies supporting these findings. [30] H 25.60 [31] 1-Me 13.50 [30] 2-Et 26.36 [31] 2-Me 11.65 [1] 2-Me 26.43 [31] 2-Ph 11.41; 13.2 [1,30] 2-Ph 25.36 [31] 1-NH 2 12.83 [31] 2-NO 2 18.75 [31] 1-NH 2 , 2-Cl 9.04 [31] 2-Cl 21.95 [31] 1,2-(NH 2 ) 2 15.60 [31] 2-Ac 18.75 [31] a In H 2 O. b In MeCN. The tautomeric equilibrium between benzimidazol-1-ols and their 1-oxide forms is very much sol-vent dependent, with the hydroxy form being favored in organic solvents.…”

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confidence: 99%