Imidazole Containing

Etintidine (84), an imidazole-containing histamine H-2 receptor antagonist, is an antiiilcer agent conceptually related to cimetidine and ranitidine. It can be synthesized by various routes one of which terminates by an addition-elimination reaction of propargylamine with substituted N-cyano-S-methylisothiourea derivative 83 to give etintidine (84) [28]. 

In this section, we restrict ourselves to the polyelectrolyte catalyst. A large number of investigations on imidazole-containing polymers has been reported. The readers are referred to other review articles6,106 l07). 

Cimetidine and other imidazole-containing H2 receptor antagonists scavenge hydroxyl radicals at a frster rate than mannitol. This activity was attributed to the methyl imidazole moiety rather than the guanidine of cimetidine (Ching etal., 1993). 

Imidazole-containing reagents have found useful applications in a variety of organic transformations. A second generation of ruthenium-based olefin metathesis catalysts... 

An early attempt to achieve metal-metal cooperation on the nonen-zymatic hydrolysis of a phosphate triester failed, probably due to the long and flexible linker connecting two imidazole-containing metal-binding sites [41]. 

The effect of structural modification to 22 on the binding efficiency and binding dynamics of hairpin DNA immobilized on metal surfaces were studied using surface plasmon resonance.124,125 The association and dissociation kinetics were analyzed using a sequential model for the binding of the imidazole containing polyamides... 

Nonetheless, to make imidazole-containing molecules, haloimidazoles may serve as electrophilic coupling partners for the Suzuki reaction. As described in section 9.1, regioselective bromination at the C(4) position could be achieved for a 1,5-dialkylimidazole using NBS in CH3CN. The Suzuki coupling of l-benzyl-4-bromo-5-methylimidazole with phenylboronic acid assembled the unsymmetrical heterobiaryl in 93% yield, whereas the corresponding Stille reaction with phenyltrimethyltin proceeded in only moderate yield (51%) [8]. 

Therefore, when we meet structures for the imidazole-containing amino acid histidine, we may encounter either of the tautomeric forms shown. Though there... 

The most efficient catalyst system for the Morita-Baylis-Hillman reaction of methyl vinyl ketone has been reported by Miller [183, 184], Use of L-proline (58) (10 mol%) in conjunction with the A-methyl imidazole containing hexapeptide 131 (10 mol%) provided an efficient platform for the reaction of 125 with a series of aromatic aldehydes 127 (52-95% yield 45-81% ee) (Scheme 52). Importantly, it was shown that the absolute configuration of the proline catalyst was the major factor in directing the stereochemical outcome of the reaction and not the complex peptide backbone. 

The imidazole-containing hypnotic/injectable anesthetic agent etomidate (58) is synthesized from 1-amino-l-phenylethane starting with triethylamine mediated displacement with chloro-acetonitrile leading to secondary amine The -enantiomer... 

Fig. 5. Single and multiple scattering pathways which make a significant contribution to the EXAFS data of an imidazole-containing compound...

Solid phase attachment of histidine-containing peptides by anchoring the imidazole ring to trityl resins has been developed for combinatorial library preparation of diketopiperazines <99TL809>. Histidine, histamine, and urocanic acid are edl imidazole-containing molecules that have been attached to a trityl-type resin to allow their application to combinatorial chemistry <99TL2825>. 

JMC5020>. Imidazole-containing diarylether and diarylsulfone inhibitors of famesyl-protein transferase has been described <99BML3301>. 

The effectiveness of the coating has been investigated by separating phenolic compounds in the nonaqueous media. The EOF was found to be anodic and dependent on the pH of the separation buffer. In anofher study [66], imidazole containing zwitterionic salt (N-3-(-triethoxysilylpropyl)-4,5-dihy-droimidazole) was attached to the silica capillary wall via the formation of a covalent bond (Figure 6.8). 

Imidazole-containing polymers and copolymers have been obtained from a variety of derivatized imidazoles, including the unsubstituted 1-, 2- and 4(5)-vinylimidazole monomers. Primary interest in these polymers has centered around metal complexation, ion exchange and catalytic properties. 

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