Imidazole derivatives reactivity

The most common methods suitable for the synthesis of different azolium compounds will be discussed here. Two routes are particularly useful for the preparation of the imidazolium salts (1) substitution reactions at the nitrogen atoms of imidazole [25] and (2) multicomponent reactions for the generation of an Af,Af -substituted heterocycle which are particularly useful for the synthesis of imidazolium salts bearing aromatic, very bulky, or particularly reactive N,N -sub-stituents (Fig. 3a,b) [26]. Both methods offer the opportunity to produce unsym-metrically substituted imidazolium salts of type 1 either by stepwise alkylation of imidazole or by the synthesis of an W-arylated imidazole derivative followed by 77 -alkylation [27]. Nevertheless, the method of choice for the preparation of the imidazolium salts 1 is the 77,77 -substitution of imidazole. Several other methods for the preparation of imidazolium salts with previously unattainable substitution patterns have also been described [28, 29]. 

The high reactivity of the dinitrate may be used to obtain heterocyclic compounds. An ingenious method of forming imidazol derivatives was developed by Payman and Fargher [102] ... 

An interesting application of the photochemical reactivity of isoxazolin-5-ones (see also Section 12.3) has been reported for the synthesis ofa series of annulated imidazole derivatives of general structure 72, which are obtained in almost quantitative yield. The methodology consists of an initial N-functionalization of the isoxazolin-5-one with a a-chloro-azaheterocycle, leading to 2-(azahetaryl)isoxazol-5(2H)-ones 71. 

Mesic, M., Deljac, A., Deljac, V., Binenfeld, Z., Kilibarda, V., Maksimovic, M., Kovacevic, V. (1991). Reactivations of acetylcholinesterase inhibited by organophosphoms compounds. Imidazole derivatives. 11. Acta Pharm. Jugosl. 41 203-10. 

Contact allergy to topical imidazoles is rare, considering how commonly they are used. The imidazole derivatives most often reported to be allergens are miconazole, econazole, tioconazole, and isoconazole. As far as cross-reactivity is concerned, in one review, there were statistically significant associations between miconazole, econazole, and isoconazole between sulco-nazole, miconazole, and econazole and between isoconazole and tioconazole (1). 

Mechanisms Metronidazole is an imidazole derivative with activity against protozoa and bacteria. The drug undergoes a reductive bioactivation of its nitro group by ferredoxin (present in anaerobic parasites) to form reactive cytotoxic products that interfere with nucleic acid synthesis. 

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