Imidazoline-5-ones

Imidazolin-5-one, 2-methyl- H NMI 5, 354 2-Imidazolin-5-one, 2-phenyl-reactivity, 5, 376 synthesis, 5, 479... 

Polyamides containing a-aminoacid units are readily obtained by reaction of bisazlactones (2-oxazolin-5-ones) with diamines. When polyamines such as diethylenetriamine (DETA) or triethylenetetramine (TETA) are used as the diamine component, the resultant polyamides readily cyclodehydrate above 200°C to produce polymers containing 2-imidazolin-5-one units in the backbone. Polyamides derived from simple diamines (e.g. 1,6-hexanedi amine) cyclodehydrate only in the presence of a suitable catalyst. Carboxylate salts and certain Lewis acids have been found to be efficient catalysts for this transformation. 

Microwave-induced 1,3-dipolar cycloadditions involving azomethine ylides have been widely reported in the literature. Bazureau showed that imidates derived from a-amino esters 120, as potential azomethine ylides, undergo 1,3-dipolar cyclo-additions with imino-alcohols 121 in the absence of solvent under microwave irradiation. This reaction leads to polyfunctionalized 4-yliden-2-imidazolin-5-ones 122 (Scheme 9.36) [87]. 

Spectroscopic evidence shows that structures 96 and 13 are the correct formulations, the latter being irrespective of the solvent. Amino derivatives appear to exist as, e.g., 20 and 21, rather than the alternative forms 97 25,26,30 Qf possible tautomers of the parent imidazolin-5-one,... 

Schollkopf et al.187) synthesized a-alkyl-a-amino acids (186) by the alkylation of chiral 1-substituted 2-imidazolin-5-ones (185), which can be prepared from a-amino acid (S)-phenylethylamides and orthoformic esters. The optical yields of the products (186) were in many cases higher than 95 %. 

The ethyl ester of 1-aminocyclopentanecarboxylic acid (1.57 g) and ethyl valerimidate (1.56 g) are dissolved in 12 ml of xylene containing 6 drops of acetic acid. After refluxing for 6.5 h, the reaction medium is concentrated under vacuum, the residue is chromatographed on silica gel using a chloroform/methanol/acetic acid mixture (94/4/2 v/v/v) as the eluent. The fraction containing the expected product is evaporated several times in the presence of xylene and then benzene in order to remove the acetic acid. 1.91 g of 2-n-butyl-4-spirocyclopentane-2-imidazolin-5-one are obtained in the form of a thick oil. 

Synthesis of 2-n-butyl-4-spirocyclopentane-l-[(2 -(tetrazol-5-yl)biphenyl-4-yl)-methyl]-2-imidazolin-5-one... 

A mixture containing 250 mg of sodium hydride (as an 80% dispersion in mineral oil) and 5 ml of DMF is prepared under a nitrogen atmosphere and a solution containing 0.97 g of 2-n-butyl-4-spirocyclopentane-2-imidazolin-5-one in 10 ml of DMF is added dropwise. The mixture is stirred for 30 min at 20°C and a solution of 1.5 g of 4-bromomethyl-2 -cyanobiphenyl in 10 ml of DMF is then added. After stirring for 1 h at 20°C, the DMF is evaporated off under reduced pressure, the residue is then taken up with ethyl acetate. 

Patent Fungicidal 2-Imidazolin-5-ones and Imidazoline-5-thiones... 

The preparation of l-hydroxy-2-(2-nicotinic-3-methoxycarbonyl)-4-isopropyl-4-methyl 2-imidazolin-5-one, (IV), is described. 

In the unsubstituted imidazolin-4(5)-ones the number of possible structures is greatly increased. Although there are only three possible forms (41-43 X = 0) for the 5,5-disubstitufed compounds, there are eight alternative forms (44-51 X = 0) for the 2,4-disubstituted imidazolin-5-ones (Scheme 17). 2-Methyl-5,5-diphenyl- and 2,5,5-triphenyI-imidazoIin-4-one both have IR spectra in the solid state which show absorptions belonging... 

The thermal rearrangement of 2,4,4-trimethyl-5-phenyl-4if-imidazole 1-oxide to 2,4,4-trimethyl-l-phenyl-2-imidazolin-5-one appears to involve a phenyl migration, while alkaline cleavage gives oximes of a-acyla-minoketones." ... 

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