Benzimidazolin-2-one

Benzimidazolinone, 1,3-dimethyl-Friedel-Crafts reaction, 5, 429 Benzimidazolinone, 1,3-divinyl-synthesis, 5, 393 Benzimidazolinone, 6-methyl-Friedel-Crafts reaction, 5, 429 Benzimidazolin-2-one polymers, 1, 281 Benzimidazolinones alkylation, 5, 390 Friedel-Crafts reaction, 5, 429 Mannich reaction, 5, 390 nitration, 5, 429 reactions, 5, 442... 

Condensation monomers having the benzimidazolin-2-one ring system have found utility as modifiers in polyester synthesis. In particular, halogenated diols (73) and dicarboxylic acids (74) may be incorporated (78MI11100) into polyethylene terephthalate) or poly(butyl-ene terephthalate) at fairly low levels to impart flame retardancy. This can be accomplished without adverse effects upon other polymer properties. 

Disposition in the Body. Readily but slowly absorbed after oral administration. About 40% of a dose is excreted in the urine in 4 days. Two metabolites which have been identified in the urine are 4-bis(4-fluorophenyl)butyric acid and l-(4-piperidyl)-benzimidazolin-2-one. Very little unchanged drug is excreted in the urine. Both unchanged drug and the butyric acid metabolite are eliminated in the faeces. 

A more highly automated synthetic route to these two classes of compounds has recently been reported utihsing a Zinsser Sophas robotic synthesiser. - A single robot was used to rapidly synthesise 96 thiobenzimidazoles derivatives 39 and a 72-membered library of benzimidazolin-2-ones 40 (Scheme 13). The transformations... 

Trimeric heterocalixarenes 170, 171 and 172 characterized by one cyclic urea, two arenes and a carbonyl bridge have been obtained by TEA HSO4 catalysed condensations of uracils, benzimidazolin-2-ones and quinazolin-2,4-dione with the dibromide 169 formed by A -bromosuceinamide bromination of benzophenone derivative 168, in turn obtained by Friedel-Crafts aroylation of 2-methylanisole with... 

Benzimidazolin-2-one refluxed 3.5 hrs. with excess POGI3 while dry HCl is passed in during the last 3 hrs. 2-chlorobenzimidazole. Y 80-90%.—Whereas the... 

Quinoxalino-benzimidazole rearrangement Chem Heteiocycl Compd 36(7) 882-883 Kalinin AA, Isaykina OG, Mamedov VA (2007) Quinoxaline-benzimidazole rearrangements in the reactions of 3-alkanoylquinoxalin-2-ones with 1,2-phenylenediamines. Chem Heterocycl Compd 43 1307-1314. doi 10.1007/sl0593-007-0198-3 Kametani T, Sota K, Shio M (1970) Studies on the syntheses of azole derivatives. Part I. Formation of l-substituted-3-hydroxy-l//-indazole and 1-substituted benzimidazolin-2-one derivatives by thermal reaction of V-substituted-/V-arylcarbamoyl azides. J Heterocycl Chem 7 (4) 807-813. doi 10.1002/jhet.5570070409... 

Electron-rich olefins are nucleophilic and therefore subject to thermal cleavage by various electrophilic transition metal complexes. As the formation of tetraaminoethylenes, i.e., enetetramines, is possible by different methods, various precursors to imidazolidin-2-ylidene complexes are readily available. " Dimerization of nonstable NHCs such as imidazolidin-2-ylidenes is one of the routes used to obtain these electron-rich olefins [Eq. (29)]. The existence of an equilibrium between free NHC monomers and the olefinic dimer was proven only recently for benzimidazolin-2-ylidenes. In addition to the previously mentioned methods it is possible to deprotonate imidazolidinium salts with Grignard reagents in order to prepare tetraaminoethylenes. " The isolation of stable imidazolidin-2-ylidenes was achieved by deprotonation of the imidazolidinium salt with potassium hydride in THF. ... 

In addition to the compounds listed above, a number of triazolium [36], thiazolium [37], and benzimidazolin-2-thione [32] derivatives as well as five-membered heterocycles with only one nitrogen atom [38, 39] or two phosphorus atoms [40] within the heterocycle, all of which are suitable for the generation of heterocyclic carbenes, have been described. 

The exclusive coordination of the C5 carbon atom in complex 48 was achieved by a reduction of the bite angle [147]. Blocking of the C4 and C5 positions as seen in benzimidazolin-2-ylidenes led to the complex with the C2-metalated NHC ligand 49 [147]. No transformation of a C5-coordinated NHC ligand into a C2-coordinated one, i.e., conversion of 46 to 47 or vice versa, has been observed so far. 

The opposite route, i.e., the withdrawal of a potential donor moiety by rearrangement and formation of a heterocycle, may also occur (Scheme 11), as shown for the formation of Si-bound l-(2-methyl-2,3-dihydrobenzothiazol-2-yl)propan-2-one (in 58) [194] and Si-bound benzimidazoline (in 59) [195] out of tridentate chelators. 

Cyclic ketene acetals can also react with amines to give 1,1-enediamines with elimination of ethylene glycol76. Treatment of 2-[(methoxycarbonyl)cyanomethylene]-1,3-dioxolane (38) with 1,3-diaminopropane or with 4,5-dimethyl-1,2-phenylenediamine gives the hexahydropyrimidine and the benzimidazoline derivatives 39 and 40, respectively (equation 11). Similarly to the reaction of ketene dithioacetals with amines, the reaction between ketene acetals and amines proceeds via monoamino-substituted intermediates and ketene 7V,Oacetals can be isolated when one molar amine is used72. 

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