Imidazole-4-acrylic acid

Imidazole-4-acrylic acid 10762 Isobutyronitrile 7687 Isopropyl isobutyrate 6502... 

Urocanic acid (imidazole acrylic acid) is converted to the imidazole propionic acid in the presence of uro-canase by oxidation of the ring carbon and reduction of the side chain (see Fig. 3-23). Urocanase has been found in the liver of mammals its acivity varies considerably, depending upon the species. Urocanase has been purified extensively from beef liver [95]. The pro-... 

So far, many kinds of nucleophiles active for hydrolysis such as imidazolyl-, amino-, pyridino-, carboxyl- and thiol-groups, have been used for preparation of hydrolase models. Overberger et al.108,1091 prepared copolymers of vinylimidazole and acrylic acid 60 (PVIm AA), by which the cationic substrate, 61 (ANTI), was hydrolyzed. This kind of copolymer is considered to be a model of acetylcholinesterase. With ANTI, the rate of the copolymer catalysis was higher than that of imidazole itself in the higher values of pH, as is seen in Table 9. In this work, important contributions of the electrostatic interactions are clear. The activity of the copolymer was not as high with the negatively charged and neutral substrates. 

The nature of the interaction between the monomer and the template is more obvious in cases where specific ionic or hydrogen bonding is possible. For example, /f-vinyl imidazole has been polymerized along a PM A A template301 202 and acrylic acid has been polymerized on a Af-vinylpyrrolidone template.3 The daughter PAA had a similar degree of polymerization to the template and had a greater fraction of isotaclic triads than PAA formed in the absence of the template. 

IM-COOH cooperation. Copolymers of 4(5)-vinyliinidazole and acrylic acid, poly(IM-ac), are considered as the His-Asp cooperation model in a-chymotrypsin. Poly(IM-ac) whose imidazole content is less than 60 mol% and neutral imidazole... 

IM-COOH-OH cooperation. Polymers such as poly(4(5)-vinylimidazole-co-7-vinyl-7-butyrolactone), poly(IM-la), and poly(4(5)-vinylimidazole-co-acrylic acid-covinyl alcohol) derived from poly(4(5)-vinylimidazole-co-methyl acrylate-co-vinyl acetate), both of which contain imidazole, carboxylic acid and hydroxyl moieties are synthesized and studied as a model of a-chymotrypsin (29). The former has a relatively ordered sequence and the latter has a random one. Results are tabulated in Table 11. The polymers cited in the Tabel contain a similarly low quantity of imidazole moiety, so that the cooperation of two subsequent imidazole moieties need not be discussed. Polymers such as L-84, L-68, M-83 and A-84 have higher catalytic activities than the polymer V-82. This suggests that the catalytic activity of the imidazole moiety in the polymers is much promoted by the carboxylate moiety in the polymers. The catalytic activities of L-84 and L-68 which have an ordered sequence are more than twice as high as that of M-83, having a random sequence. From these results it is concluded that the introduction of the hydroxyl moiety which has little cooperative effect on the imidazole moiety in V-82 in this reaction conrfition into imidazole and carboxylate — containing polymer, increases... 

A clear-cut molecular relay system is materialized with the combination of two nucleophile moieties such as hydroxamic acid and imidazole introduced in a polymer (38, 40, 82). Hydroxamate anion has a high nucleophilicity but deacylation of the acylhydroxamate is very slow. The significance of the deacylation step in the hydrolysis in polymer catalyst is pointed out in several works, for example, the deacylation of acetylated poly(4(5)-vinylimidazole) (83,84) and the aminolysis of nitrophenyl ester of poly(styrene-co-acrylic acid) (85—87). To promote the deacylation velosity of the acylated hydroxamic acid imidazole moiety is introduced in the hydroxamic acid-containing polymer. The polymers are shown in tire following page. 

The significance of the coulombic field is observed (79). Figure 9 shows the catalytic activities of poly(4(5)-vinylimidazole-co-acrylic acid), poly(IM-ac), and low molecular weight imidazole derivatives in hydrolyses of various substituted phenyl acetates of which leaving groups have different activities. 

In an attempt to synthesize a component 50 of exochelin MN (51), the regioin-versed AA of imidazol acrylates 49 under the influence of the (DHQD)2AQN ligand was investigated (Scheme 9). While hydroxyphenyl-substituted substrates such as 48a and 48b gave satisfactory yields (45-55%), regioselectivities (3 1 — 1 0), and enantioselectivities (84-86% ee), no reaction was observed with imidazole-substituted substrates like 48c [71], However, the synthesis of the indole-substituted amino acid 52, a component of cyclomarin A (53), was achieved in 36% yield (Scheme 9) [72], The diastereoselectivity of the AA reaction was determined to be 95 5. 

Fig. 33 Illustration of the two extremes, homogeneous and segregated, of the distribution of hydrogen-bonded side chains along the backbone in the case of a substoichiometric composition. System PAA(LC) investigated consists of poly(acrylic acid) and side chains containing cyanobiphenyl mesogens connected with an alkyl chain to imidazole-based hydrogen-bond acceptors (Scheme 10c). Reprinted with permission from [242]. 2006 American Chemical Society...

A number of methods employ an imidazole-2-thione or related compound with a bifunctional reagent to build the thiazine ring in one or two steps. Treatment of (682) with acrylyl chloride directly produced (683) (64JOC1720). Substituting acrylic acid under catalysis allows isolation of the S-alkylated intermediate, which cyclized to (683) upon heating (64JOC1715). 

Other activated acrylate derivatives have been used more successfully to minimize formation of 60 with concommitant increase in reaction yield.28 The corresponding anhydride (X = H2C=CHC02-), mixed anhydride (X = EtOC02-), azide (formed by treatment of acrylic acid with (PhO)2P(0)N3 (DPPA)), and the acyl imidazole all enhanced the aza-annulation process. In general, substitution at the a-position had minimal effect on the outcome of the reaction, but was accompanied by variations in the ratio of 61 to 62. However, when the crotyl derivative was used (R3 = Me) the aza-annulation process was significantly slower, and when compared to the acrylic acid reagents (R3 = H), the amount of 60 was increased relative to the amounts of 61 and 62... 

The hydrogen bonding between carboxylic acid and imidazole is also useful. A complex derived from poly(acrylic acid) and bis(imidazolyl)biphenyls forms a smectic A phase [89]. 

Letsinger and Klaus investigated the solvolysis of poly(acrylic acid-co-2,4-dinitro-phenyl p-vinylbenzoate) 9 catalyzed by partly protonated poly(N-vinylimidazole) 4 (57). The poly(N-vinylinudazole) showed a sufficient activity at the imidazole unit concentration much lower than that of N-methylimidazole 11 (Table 4—1), and the rate attained a limiting value at high catalyst concentrations. The rate saturation was... 

SSlimidzu et al. 83) also studied the c ytic solvolysis by copolymers of vinylimidazole and acrylic acid. The Michaelis-Menten type behavior was observed for the solvolysis of ANTI 32 but not for that of PNPA 3 in 100% aqueous systems, in contrast to the second-order kinetic behavior in 28.5% ethanol-water as reported by Overberger et al. 80). Substrate binding as given by 1/Am fias maximal at 25 to 30 mol% imidazole content, and the intracomplex rate for the neutral imidazole unit was minimal at 20 to 30 mol% imidazole contents. The resulting overall efficiency simply decreased with increasing imidazole contents. 

Imidazole-5-Acrylic Acids Potent Nonpeptide Angiotensin II Receptor Antagonists Designed Using a Novel Peptide Pharmacophore Model. 

The supramolecular self-assembly between PS-Zi-poly(acrylic acid) (PAA) and imidazole-terminated hydrogen-bonding mesogenic groups was also used to prepare non-azo LCBCs (Chao et al., 2004). Owing to the attached LC properties, the nanostructures in the LCBC films obtained can be oriented by using an alternating current (AC) electric field, in a direction parallel to the electrodes. 

CAS 104-98-3 EINECS/ELINCS 203-258-4 Synonyms 4-lmidazoleacrylic acid lmidazoie-4-acryiic acid 3-lmidazol-4-yl acrylic acid 3-(1H-lmidazol-4-yl)-2-propenoic acid 2-Propenoic acid, 3-(1H-imidazol-4-yl)-Urocaninic acid Classification Org. compd. 

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