Imidazole 5-amino-4-carboxylate

Imidazole-4-carboxylic acid, 5-amino-cyclization, 5, 583 decarboxylation, 5, 434—435 ethyl ester diazotization, 5, 414 synthesis, 5, 477... 

In the reaction of an aminoalcohol with a methyl imidazole-AT-carboxylate or tert-butyl imidazole-AT-peroxycarboxylate, selective acylation of the amino function can be achieved11903 to give the carbamate and peroxycarbamate, respectively, the hydroxy groups of which can be further acylated ... 

Vobsd — 7iaVN(peptide) + 7ibvx(amino) + 7lcVX(imidazole) 77dV0(carboxylate) +... 

Imidazole-2-carboxylates can be made by amidine cyclization (see Section 2.2.1 and Table 2.2.2), by reaction of an aminocarbonyl compound with thioxamate (see Section 4.1 and Scheme 4.1.6), and from 1-cyano-or 1-carbethoxy-substituted 4-amino-2-azabutadienes (see Section 3.2 and Scheme 3.2.3). An improved amidine cyclization treats trichloroacetonitrile with ami noacetaldehyde dimethyl acetal to give the amidine (5), which cyclizes with trifluoroacetic acid at room temperature to give 2-trichloromethylimidazole (Scheme 8.3.2). This is not purified, but converted immediately into ethyl imidazole-2-carboxylate or imidazole-2-carboxylic acid in high yields [10],... 

The isomeric 1-suhstituted imidazole-5-carboxylates are made by cyclization of 3-amino-2-alkylaminopropanoic acids with triethyl orthoformate followed by active manganese dioxide oxidation of the imidazoline product (see Section 3.1.1), or from IV-substituted glycine esters, which are formylated, converted into the enolates and then condensed with potassium thiocyanate... 

Heteroarylamines, for example 1195, react with (dimethylamino)propenoate 1196 to yield an imidazolecarboxylate 1199. The imidazole ring is formed via the intermediate diaminoalkenoate 1197, which undergoes an intramolecular Michael addition followed by a retro-aldol-like reaction (Scheme 294) <1998JHC1527>. Similarly, 4-dimethyl-amino-2-aza-l,3-dienes 1200, serving as y-dielectrophiles, condense with amines or hydrazines neat at 70 °C to form A -substituted imidazole-4-carboxylates 1201 in 60-75% yields (Scheme 294) <1999TL8097>. 

Novel 2 -modified nucleoside triphosphate derivatives incorporating imidazole, amino or carboxylate pendant groups attached to the 5-position of pyrimidine base through alkynyl and alkyl spacers (115) have been synthesised. In one reported procedure, the appropriately protected modified nucleoside was phosphorylated with POCI3 in triethylphosphate in the presence of 1,8-bis(dimethylamino)naphthalene. The phosphorochloridate intermediate was then condensed in situ with tri-n-butylammonium pyrophosphate to yield the protected triphosphate analogue that was then deprotected. In another... 

The second method employed methyl 4-amino-imidazol-5-carboxylate (72) which gave l-R-2-R -4-isothiocyanato-imidazole-5-carboxylate (73) with thiophosgene and methyl l-R-2-R -4-[l-(3-hydroxyethyl)thioureido]imidazole-5-carboxylate 74 with... 

To discuss acid-base catalysis, it is helpful to recall the definitions of acids and bases. In the Brpnsted-Lowry definition, an acid is a proton donor and a base is a proton acceptor. The concept of general acid-base catalysis depends on donation and acceptance of protons by groups such as the imidazole, hydroxyl, carboxyl, sulfhydryl, amino, and phenolic side chains of amino acids all these functional groups can act as acids or bases. The donation and acceptance of protons gives rise to the bond breaking and re-formation that constitute the enzymatic reaction. 

Maier and Endres showed [44] that irradiation of imidazole-2-carboxylic acid, matrix-isolated at 10 K, with a wavelength of 254 nm leads to decarboxylation and the formation of a complex between the parent imidazol-2-ylidene and carbon dioxide Maier applied a similar approach to the formation of the parent thiazol-2-ylidene. [45] This matrix-isolation approach is the only practical route to diaminocarbene derivatives with hydrogen substituents on the amino groups and it would be valuable to generate diaminocarbene itself this way. The precursor amidinoformic acid is known, [46] but is apparently too insoluble in suitable media for the matrix method to be applied. Both diaminocarbene [47] and the parent imidazol-2-ylidene [48] have been detected by neutralisation-reionisation mass spectroscopy. 

Copolymerizing DMAEMA with monomers that possess primary amino, imidazole or carboxylic functionalities has been investigated as well, in order to enhance the endosomal escape, but all of the researched copolymers showed limited transfection/ ... 

Amino-5-(2-amino-l -hydroxyethyl) -4,5-dihydro-lH-imidazole-4-carboxylic acid, 9CI. Geamine. Roseonine [29307-61-7]... 

Proteins are built up of a-aminoacids differing in the presence of reactive groups such as amino, carboxyl, amido, hydroxyl, thiol and imidazole groups. The structure of proteins is an extended chain of aminoacid residues joined by amide linkages which are readily degraded by enzymes, particularly proteases. 

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