1-Benzoyl-2- imidazole

Die Umwandlung von (2-Oxo-alkyl)-l, 2,4-triazolium-Salzen mit Natriumhydrid in Dimethyl-formamid fiihrt zu 4-Acyl-5-amino-imidazolen. Diese Reaktion verlauft iiber offenkettige N-Cyan-formamidine, was in einem Beispiel durch Isolierung des N-Cyan-formamidins und dessen thermische Cyclisierung zum 4-Acyl-5-amino-imidazol nachgewiesen wurde. Die Ausbeuten liegen im allgemeinen um 30%. In einem Fall wurden 60% Ausbeute erzielt [5-Amino-l-(4-chlor-benzyl)-4-(2,4-dichlor-benzoyl)-imidazol Schmp. 220°]373 ... 

The hydrolysis of acetyl- (150 R = MeCO) and benzoyl-imidazoles (150 R = PhCO) involves the reversible addition of water to the imidazole to give the T=. At low acidities the decomposition of this is the slow step but, as the acidity increases and water activity decreases, its formation becomes rate determining.128 By contrast, the hydrolysis reactions of the (V-acyl derivatives of 2,4,5-triphenylimidazole proceed in a concerted maimer and do not involve tetrahedral intermediates.129... 

The acetylation of L-rhamnal and L-fucal has been studied. When acetyl chloride, N-acetylimidazole, benzoyl chloride, or -benzoyl-imidazole were used, the esterification of L-rhamnal occurred primarily at the allylic hydroxy group. With acetic anhydride-pyridine it was mainly the homoallylic hydroxy group which ester-ified. Selective acylations of L-fucal could not be achieved since acyl migration from 0-3 to 0-4 occurred. The ratios of the products were studied under various conditions of solvent, temperature, and time. 

Nltro-l6ienyI]-2-[4-nitro-benzOyl]-imidazol 24II114.. 

Azoles containing a free NH group react comparatively readily with acyl halides. N-Acyl-pyrazoles, -imidazoles, etc. can be prepared by reaction sequences of either type (66) -> (67) or type (70)->(71) or (72). Such reactions have been carried out with benzoyl halides, sulfonyl halides, isocyanates, isothiocyanates and chloroformates. Reactions occur under Schotten-Baumann conditions or in inert solvents. When two isomeric products could result, only the thermodynamically stable one is usually obtained because the acylation reactions are reversible and the products interconvert readily. Thus benzotriazole forms 1-acyl derivatives (99) which preserve the Kekule resonance of the benzene ring and are therefore more stable than the isomeric 2-acyl derivatives. Acylation of pyrazoles also usually gives the more stable isomer as the sole product (66AHCi6)347). The imidazole-catalyzed hydrolysis of esters can be classified as an electrophilic attack on the multiply bonded imidazole nitrogen. 

Imidazole, 2-aryl-4-phenyl-5-trifluoromethyl-synthesis, 5, 483 Imidazole, azido-reactions, 5, 442 Imidazole, 2-azido-, 5, 415 cyclization, 6, 980 reactions, 5, 96 with sodium, 5, 442 tautomerism, 5, 371 Imidazole, benzoyl-IR spectra, 5, 30 Imidazole, 2-benzoyl-4-phenyl-... 

Most of the substrates that give both types of cycloaurated complexes are limited to pyridine derivatives, although recently a few exceptions have been reported with thiazoles and imidazoles. The reaction of substituted pyridine ligands such as phpy,1 49,1924 2-benzoyl pyridine,1924 2-anili-nopyridine,1925,1926 l-(2-pyridylamino and 2-pyrimidinylamino)naphthalene, 7 2-phenoxypyri-dine,1811 2-(phenylsulfanyl)pyridine,1925 2-(2-thienyl)pyridine, 8 2-(3-thienyl)pyridine,1928 2-(alkylsulfanyl)pyridine,1929 or papavorine1930 at room temperature yields the nonmetallated compounds which, upon heating, are transformed into the metallated complexes [Au(N,C)Cl2], The process with phpy is illustrated in Scheme 21. 

Sapse et al.41b performed ab initio calculations on benzene-benzene as a model for the interaction between the a phenylalanine residue and the benzoyl portion of a typical folate compound. In addition, that study examined the complex formed hy a benzene ring and a polar serine which acts as a hydrogen donor, between a benzene ring and the amino group of a meta diamino-imidazole group (present in some anti-folates) and between serine as a hydrogen donor and the diamino-imidazole group as the electron donor. 

In what was intended as another experimental probe to ascertain whether a concerted or stepwise mechanism was involved in substitution reactions of arenesulfonyl chlorides, Rogne (1975) measured the enthalpies of transfer from propanol to acetonitrile for the transition states, SAH, for the reaction of imidazole with (a) benzoyl chloride and (b) benzenesulfonyl chloride. He found that SAH was considerably more negative for the reaction involving the sulfonyl chloride than for the one involving benzoyl chloride. This means that the transition state for attack of imidazole on benzenesulfonyl chloride is considerably better solvated by acetonitrile relative to its solvation by propanol... 

In the presence of zinc chloride, benzil and 1,1-diphenylmethanamine yield a small amount of 2,2,4,5-tetraphenyl-2//-imidazole (7, Scheme 2). A claim d to have isolated a 2-benzoyl-2//-imidazole from benzil monohydra-zone and S4N4 was later shown to be in error. ... 

Phenyl-glykolsaure-nitril laBt sich in Diethylether unter Durchleiten von Chlorwasserstoff zu 13% zu 2-Benzoyl-4(5J-phenyl-imidazol umsetzen229. 

Aus Methylamino-essigsaure-ethylester (Sarkosin-ethylester) bzw. 2-Methylamino-l-oxo-l-phenyl-ethan werden mit Dithiocarbonsaure-cyanimid-dimethylester 4-Amino-5-methoxycar-bonyl-l-methyl-2-methylthio-imidazol bzw. 4-Amino-5-benzoyl-l-methyl-2-methylthio-imidazol hergestellt303. 

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