2- 2- benz imidazole

Similar reactions of been described leading to benz[e]imidazoles, benz[g]indazoles, and benz[f]isoquinolines. 

Chemicai Name 1 -[ 1 -[4-(4-fluorophenvl)-4-oxobutvl] -4-piperidinyl] -1,3-dihydro-2H-benz-imidazol-2-one... 

N l(4-fluorophenyl)melhy ]-3-nitro-2,6-pyridinediamine (Cj2HjiFN402 33400-49-6) see Flupirtine 4-(4 fluorophenyl) a methyl-l-piperazinepropanamine (C14H22FN3 27367-89-1) see Niaprazine l-[(4 fluorophenyl)methyl]- -4-piperidinyMH-benz-imidazol-2>amine... 

Carbene complexes have also been prepared by transmetallation reactions. Lithiated azoles react with gold chloride compounds and after protonation or alkylation the corresponding dihydro-azol-ylidene compounds, e.g., (381) or (382), are obtained.22 9-2264 Silver salts of benz-imidazol have also been used to obtain carbene derivatives.2265 Mononuclear gold(I) carbene complexes also form when trimeric gold(I) imidazolyl reacts with ethyl chlorocarbonate or ethyl idodate.2266,2267 The treatment of gold halide complexes with 2-lithiated pyridine followed by protonation or alkylation also yields carbene complexes such as (383).2268 Some of these carbene complexes show luminescent properties.2269-2271... 

The most common ligands are those derived from imidazole and benzimidazol (Scheme 54), followed by the (benz)thiazols. The free Wanzlick-Arduengo carbenes can be isolated and employed for the synthesis of the complexes, but often it is more convenient to prepare the carbenes in situ from the dimers or the corresponding onium salts, or to use carbene-transfer reactions.256-259... 

Oxazoles and benzoxazoles are viable participants in the heteroaryl Heck reactions. In their monumental work published in 1992, Ohta and colleagues demonstrated that oxazoles and benzoxazoles, along with other rc-sufficient aromatic heterocycles such as furans, benzofurans, thiophenes, benzothiophenes, pyrroles, thiazole and imidazoles, are acceptable recipient partners for the heteroaryl Heck reactions of chloropyrazines [22b]. Therefore, treatment of 2-chloro-3,6-diethylpyrazine (27) with oxazole led to regioselective addition at C(5), giving rise to adduct 28. By contrast, a similar reaction between 2-chloro-3,6-diisobutylpyrazine (29) and benz[fc]oxazole took place at C(2) exclusively to afford pyrazinylbezoxazole 30. 

The 4f/-imidazoles have not previously been reviewed comprehensively. In earlier reviews on the H compounds " isolated examples are discussed, although in a later work a more thorough treatment has been given. An attempt has been made in the present article to include all known AH-imidazoles using a CAS on line substructure computer search. Chemical Abstracts have been covered up to and including Issue 4 of Volume 97, and a few additional references have been included directly from the more common international journals. Structures having exocyclic double bonds have been excluded benz-fused systems cannot be drawn in this series. 

Diamino-2,l>3-benzothiadiazole 201 undergoes cyclization on reaction with selected aromatic aldehydes <2004T2953>. Thus, reactions with pyrene-l-carboxaldehyde or naphthalene-1-carboxaldehyde in refluxing toluene produce the corresponding imidazoles 202 in moderate yields, whereas reactions with /i-(Ar,Ar-dimethylamino)benz-aldehyde and /i-[Ar,Ar-di(4-methylphenyl)amino]benzaldehyde under similar conditions gave the corresponding 5-imino derivatives 203 (Scheme 13). 

SchlieBlich sei die Umsetzung von l-Benzyloxy-2-hydroxy-imidazol mit Natriumhydroxid in Methanol zu 2-Hydroxy-imidazol erwahnt, die in 51% Ausbeute unter Abspaltung von Benz-aldehyd verlauft512. 

Imidazole sind sehr oxidationsstabile Verbindungen. So bleibt z. B. bei der Oxidation von Benz-imidazolen zu 4,5-Dicarboxy-imidazolen der Imidazol-Ring intakt, wahrend der Benzol-Ring oxidativ abgebaut wird (s. S. 173). 

Die Carbonyl-Absorptionen der 2-Oxo-2,3-dihydro-benzidimidazole finden sich in einem wei-ten Bereich (von 1770-1675 cm- x)39, zu den Infrarot-CO-Banden acylierter 2-Hydroxy-benz-imidazole s.668. 

NHjVCH"C6H5 C6H5 H3C—COOH/ H3C-COONa 4 h Riickfl. l-Benzyliden-3-phenyl-1H-< imidazo [7,5-a]benz-imidazol) V-CH-C6H5 H5C6 90 270 80... 

Dimethyl-2-(2-methoxy-4-methylthio-phenyl)-6-oxo-1,5,6,7-te trahydro-(pyrrolo[2,3-J]benz-imidazol> 81% Schmp. 293-295°... 

Amino-l-methyl-benzimidazol wird von Benzoylchlorid erstaunlicherweise am endocycli-schen N-Atom angegriffen. Man erhalt zu 90-93% 2-Amino-l-benzoyl-3-methyl-benzimidazo-lium-chlorid. Erst beim Erwarmen mit Basen lagert es sich in 2-Benzoylamino-l-methyl-benz-imidazol um554 ... 

Eine effektive, reversible Schutzgruppe fur Benzimidazole ist l-Chlormethoxy-2-trimethylsilyl-ethan (SEM — Cl), das in Dimethylformamid zu l-[(2-Trimethylsilyl-ethoxy)-methoxy]-benz-imidazol [50% Sdp. 220°/0,2 Torr (26,7 Pa)] kondensiert. Die so geschiitzten Heterocyclen sind wesentlich weniger feuchtigkeitsempfindlich als die (l-Diethoxy-methyl)-Derivate (s.S.357). Man kann die SEM-Schutzgruppe in siedendem Tetrahydrofuran mit Tetrabutyl-ammonium-fluorid leicht wieder entfernen508. 

Qc/- CljC-O-CO-CI THF 20 Aktivkohie l-Chlorcarbonyl-2-hydroxy-benz- imidazol 67 193-197 (Zers.) 603... 

Addiert man Aryl-isocyanate an Triphenyl-phosphan-(2-benzimidazolyl-methylimin) (I), so erhalt man 2-Aminocarbony 1-1 -arylimino-2,3-dihydro-lH-[Pg.357]

Carboxy-benzoyl)-2-dimethylamino-benz-imidazol (Rohprodukt)... 

Alkyl-3-oxo-2,3-dihydro-<(benzimidazolo[l,2-d]-l,2,4-thiadiazol> eliminieren beim Erhitzen auf 160" Alkyl-isocyanat und Schwefel. Als Zwischenprodukt wird ein 1,2-Dehydro-benz-imidazol formuliert. Ohne Zusatz von Nukleophilen trimerisiert es zu Tribenzimidazo[l,2-a 1, 2 -c /",2"-e]triazin (Schmp. 380°) anwesende Phenole addieren sich zu 2-Ary loxy-benz-imidazolen653 z.B. ... 

Die Nitrosierung von 2-Amino-1-methyl-benzimidazol fiihrt zu l-Methyl-2-nitroswnino-benz-imidazol, das thermisch in Benzol Stickstoff abspaltet und aryliert wird638. 

Pd poly(benz-imidazole) nitrile oxidation of alkenes to ketones [96]... 

Cyclodesulfurization of thioureide 213 with lead acetate or yellow mercuric oxide in methanol, followed by acetylation with acetic anhydride, affords two products, acetylaminobenzimidazole and (glycosylamino)benz-imidazole 216 however, the latter was formed in very poor yield.99 The... 

Aryl-5,6-dihydrobenzo[4,5]imidazo[l,2-C]-quinazolines Isatoic anhydride could also be reacted with amino-, hydroxyl- or thiolanilines to form 2-(2-aminophenyl)benz-imidazoles, oxazoles or thiazoles, Scheme 5.38. In the case of 2-(2-aminophenyl)benzimidazoles (X=N), the product was formed after 3 min at 150°C in acetic acid. The products could subsequently be further elaborated 6-aryl-5,6-dihydrobenzo[4,5]imidazo[l,2-C]quinazolines, a four ring system, was formed by treatment of the 2-(2-aminophenyl) benzimidazole (X=N) with different aldehydes in acetic acid at 150°C for 5 min (J. Westman, and K. Orrling, Personal Chemistry, Uppsala, Sweden, unpublished results). Fifteen compounds were synthesised in 20-75% overall yield. This 3 + 5 min procedure should be compared to the conventional heating protocol developed by Devi and co-workers57, where each reaction step was run overnight to eventually afford the products in only 30-50% yield. 

The prefix benz- in benzimidazole (structure given in text) signifies that a benzene ring is fused to an imidazole ring. By analogy, benzoxazole has a benzene ring fused to oxazole. 

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