Imidazole cyanogen bromide

Azoles can form stable compounds in which metallic and metalloid atoms are linked to nitrogen. For example, pyrazoles and imidazoles Af-substituted by B, Si, P and Hg groups are made in this way. Imidazoles with a free NH group can be Af-trimethylsilylated and Af-cyanated (with cyanogen bromide). Imidazoles of low basicity can be Af-nitrated. 

The imidazole ring system provides the nucleus for two diuretic agents with structures unusual for that activity. Reaction of the N-cyanoaniline 140 (obtainable from the aniline (139) and cyanogen bromide) with N-methylchloroacetamide leads to the heterocycle 142. The sequence can be rationalized by... 

The preparation of a pair of iminohydantoins invokes the addition of amide nitrogen to a cyano group for formation of the imidazole ring. The products exhibit unexpectedly quite different biological activities. Reaction of the cyanamide (92-1) from para-chloroaniline and cyanogen bromide with A-methylchloroacetamide (92-2) can be visualized to lead initially to the alkylation product (92-3). Cyclization by addition to the nitrile group then affords clazolamine (92-4) [98], a compound described as a diuretic. 

Similar imidazolium ylides are implicated in the aroylation of TV-phenyl benzimidoyl chlorides (92CPB2627), and in reactions of 1-substituted imidazoles with cyanogen bromide to form 2-cyano- or 2-bromo-imidazoles (88S470). 

Techniques for the coupling of antibodies to cellulose particles or tubes were initially unreliable, time-consuming, and hazardous as they involved toxic reagents such as cyanogen bromide. A simple and convenient method is now available which employs I,I-carbonyldi-imidazole to couple antibody to microcrystalline cellulose. 

Direct Af-cyanation is possible when cyanogen bromide reacts with an imidazole or benzimidazole having a free NH group (Scheme 28) (80H(14)1963). 

Interest in cyanogen bromide as a brominating agent for imidazoles has been rekindled. It seems that bromo products can be made in this way, for example, 1-benzylimidazole reacts with cyanogen bromide in the presence of 4-dimethylaminopyridine to give l-benzyl-2-bromoimidazole, perhaps via an ylide mechanism. Cyanogen chloride and the pre-formed adduct of cyanogen bromide and... 

Cyanogen bromide in alkali joins together amino and isopropylsulphonyl-amino groups as a fused 2-aminoimidazole ring without external heating [3887]. The oxazolinone (76.8) behaves as a lactone this is cleaved, and converts the diamine into an imidazole ring the remainder of the oxazolinone is attached to C-2 of the benzimidazole [3088]. 

Indirect routes232 can be employed to synthesize JV,JV-bis(TMS)-carbodiimide (458) (a) by applying silver imidazole to 7V,jV-bis(TMS)-thiourea (457) (equation 213), (b) by reaction of Me3SiCl with silver cyanamide (459) (equation 214), (c) by reaction of Me3SiCl with hydrogen cyanamide (460) in the presence of a tertiary amine (equation 215) and (d) from cyanogen bromide (461) and hexamethyldisilazane (405) (equation 216). 

Adenosine 3 -monophosphate is readily cyclized to the 2, 3 -monophosphate by cyanogen bromide in imidazole buffer. 93 It appears that both N-cyanoimidazole and diimidazoleimine are formed, and both reagents can effect the cyclization in aqueous solution, with N-cyanoimidazole being the more effective reagent, particularly in the presence of divalent metal ions (Cu2+, Ni2+, Zn +). They may represent useful alternatives to DCC or carbonylbis(imidazole) in condensation reactions. 

Cyanation. This reagent is prepared from imidazole and cyanogen bromide. It donates the cyano group to various nucelophiles such as amines, thiols, and RMgX (or RLi). 

The zwitterionic perhydropyrrolo[l,2-c]imidazole (122) has been obtained by reaction of 2-aminomethylpyrrolidine-5-carboxylic acid chloride with sodium hydroxide and cyanogen bromide (Scheme 23) <84MI 802-02>. 

Scheme 6), presumably by way of the 2,2 -cyclonucleosides. Treatment of uridine with either diirainosuccinonitrile or cyanogen bromide gave as major product 2,2 -anhydrouridine-3 0-carbaraate, probably via the 2, 3 -cyclic imidocarbonate. An imidazole... 

Kennedy and Paterson [99] used a similar approach and rolled a rod from a paper-like cellulose sheet. After cyanogen bromide or l,l -carbonyldi-imidazole activation, protein A and protein G were immobilized onto the cellulose and the column was successfully used for the affinity separation of immunoglobulin G (IgG). 

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