Imidazole compounds

Hartman, P. E., Hartman, Z., and Ault, K. T. (1990). Scavenging of singlet molecular oxygen by imidazole compounds high and sustained... 

The most extensive development of pharmacological inhibitors of MAPK cascades members has been for p38 (Table 1) [3]. Small-molecule inhibitors have been developed for two p38 isoforms (a and (3). Pyridinyl imidazole compounds have been known to block inflammation since the early 1970s. Structural analyses have revealed that p38 kinase inhibitors binds to the ATP-binding pocket of p38 thereby acting as competitive inhibitors. The p38 kinase inhibitor SB202190 is able to bind both the low-activity nonphosphorylated... 

All synthetic approaches to imidazo[2,l-f][l,2,4]triazines published during recent years utilize the ring closure of the six-membered triazine ring by conversion of a properly functionalized imidazole compound. 

Bazureau s group reported extensive work with TSILs for synthesis of various 4-thiazolidinones, 1,4-dihydropyridines, 3,4-dihydropyrimidin-2(lH)-ones and polyhydroquinones. They functionalized imidazole compounds with esters, which were then reacted with reagents to afford the target compound. They report that microwave dielectric heating is a useful aid to rapidly produce the desired product in high yields. 

Histamine is an imidazole compound, formed by decarboxylation of the amino acid L-histidine, a reaction catalyzed by the enzyme histidine decarboxylase. 

Tsuji, K., Terasaka, T., Nakamura, K. (Fujisawa Pharmaceuticals Corporation, Ltd.) Imidazole compounds and their use as adenosine deaminase inhibitors, WO 0153271. 

Boit (97) and Leete (98) suggested that in the biogenesis of pilocarpine, the imidazole compound 47 reacts with acetylacetic acid (48). It should be remarked that the phosphate of 47 is assumed to be an intermediate in the biogenesis of histidine. The reaction between the methylene group in 48 and... 

Only four imidazole compounds have been found to undergo skeletal rearrangements.z47,249... 

The two carbene units can be embedded in a (macro)cyclic ring system known as a cyclophane. A standard procedure for the synthesis of such a system starts with a,a -dibromoxylene and potassium imidazolide [368]. Cychsation can be achieved by reacting the bis-imidazole compound with a second equivalent of a,a -dibromoxylene (see Figure 3.116). The cyclic bis-imidazolium cyclophane can then be reacted with paUadium(II) acetate to form the palladium complex [369,370]. The silver(I) and gold(I) complexes are accessible from the reaction with silver(I) oxide [371] and the usual carbene transfer reaction to gold(I) [372]. 

As described in a previous section, the imidazole group of a histidyl residue is involved in a most direct fashion in the catalytic action of hydrolytic enzymes (see Table 2—1). This fact attracted mudi attention among phyrical organic chemists, and imidazole and imidazole compounds became the first organic bases to have been established as catalysts for ester hydrolysis. Since the weakly basic imidazolyl group is not capable of directly displacing the much mtxe basic alkoxide ions from normal esters, most studies have dealt with the catalysis of the hydrolysis of activated esters, such as phenyl acetates and thiol esters ... 

Table 5.19 Commercial products containing imidazole compounds...

Reference has been made to 1,3,5-tribromotriazoIe and 1,3-dichlorotriazole which act as halogenating agents (Section 4.12.3.2.2). Transfer of N-acyl functions to 1,2,4-triazole has been illustrated in Scheme 28 but AT-acyltriazole and especially carbonylditriazole (83) may be used similarly to the analogous imidazole compounds (79LA1756) except that the latter are more economical. 

In general, the imidazole compound is treated with excess hexamethyldis-ilazane under reflux on an oil hath or heating mantle for several hours. The product is isolated by fractional distillation. For example 1-lrimelhyl-silylimidazole is made from imidazole (1.3.6 g, 0.20 mol) and hexamelhyldi-silazanc (24.2 g, 0.15 mol) heated for lOh. The product (85% yield) has a b 2 of 91°C. 

Imidazoles. Compounds 46 can be reduced to aldehydes with LiAlH4. 

S.E. Severin, Problems concerned with the biological activity of naturally occuring imidazole compounds. Proc. Plen. Sess. Vf Int. Biochem. Congr.. NY., 1964, pp. 45-61. 

A. Urazaev et al.. Imidazole compounds as the natural factors controlling NQ-synthase in skeletal muscles of rat. Neurochemistry Moscow (Russian), 12 (1995) 46-50. 

Some examples of urea foams prepared by the water-isocyanate reaction are as follows. ICI disclosed the foam prepared by the water-isocyanate reaction in the jn-esence of imidazole compounds (137). PRB NV disclosed a foam j epared in the presence of water-soluble saccharide and polyol (139). Bayer AG disclosed a foam prepared by using 1.5 to 50 parts of alkanolamine with water and 100 parts of polyisocyanate (138). Schaum Chemie disclosed foams prepared by using lower alkanols and alkylene diols (140). 

Starting with the benzyl-imidazole (compound 1), which binds to angiotensin II (All) receptor but exhibits a very poor potency, Duncia et supposed that a second acidic group (compound 2) would provide, at physiological... 

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