Methylene imidazolidinones

Sequential 3 -l- 2-cycloaddition/rearrangement reaction of imidazolone nitrones with allenoates has been reported to give methylene imidazolidinones (Scheme 39). ... 

Figure 15.1 Reactions of formaldehyde with peptides and amino acids. Shown are the four types of reaction products seen when peptides or amino acids are treated with formaldehyde in aqueous solution. These reaction products are methylol (hydroxymethyl) adduct (reaction 15.1), Schiff-base (reaction 15.2), 4-imidazolidinone adduct (reaction 15.3), and one type of methylene bridge [cross-link] (reaction 15.4).

The thiocarbonyl group is a highly reactive dipolarophile and in general this group dominates the reactivity of nonenolisable exocyclic thioketones as illustrated for the systems shown 5-methylene-2-thioxo-l,3-thiazolinin-4-one (260) (161), pyrimidone-2- and -4-thiones (261, 262) (134), pyrazolo[l,5,4-e/][l,5]benzodi-azepin-6-thione (263) (162). 2-Thiono-4-imidazolidinone (264) also gave a C=S cycloadduct as expected but, in the case of the analogue 265 with an additional exocyclic methylene group, the latter proved to be more reactive (163). 

In the absence of basic catalysts, propargylamines react with isocyanates to give ureas. However, in the presence of basic catalysts, 4-methylene-2-oxazoli-dinones and 4-methylene-2-imidazolidinones are obtained directly or through the urea derivative [27] (Eq. 18). 

Methyl-1,3-diisopropylpseudourea, 170 Methylene compounds, nitrosation of, 395 4-Methylene-2-imidazolidinones, 140 4-Methylene-2-oxazolidinones, 140 2-Methyl-5-ethylpyridine, 96... 

Not only a zinc-copper couple, but also a zinc-lead couple forms a gem-dimetal species from diiodomethane, according to the 1975 Nysted patent5. He also insisted that treatment of dibromethane with a zinc-lead couple in THF at 80 °C forms a characteristic gem-dizinc species 1 (equation 3). However, there was no further evidence concerning the structure except H NMR data, which was not enough for the complete structural determination. The obtained compound was definitely a gem-dizinc species, but the written structure 1 was not fully characterized. The white solid 1 is obtained as a dispersion in THF, and does not dissolve in DMF and DMI (l,3-dimethyl-2-imidazolidinone). This THF dispersion is commercially available from Aldrich Co. as Nysted reagent. Nysted also showed that this dizinc compound is effective for the methylenation of a-hydroxy ketone moiety in steroid derivatives5. 

The solution of 5.0 g of l-(4-pyridyl)-2-imidazolidinone in 45 ml of water is hydrogenated over 0.8 g of 10% ruthenium on carbon at 120°C and 120 atm until the hydrogen absorption ceases. It is filtered, the filtrate evaporated, the residue taken up in chloroform, the solution dried, evaporated to yield the 1-(4-piperidyl)-2-imidazolidinone, melting point 155°-157°C (recrystallized from methylene chloride-petroleum ether). 

The data of the NMR spectra of l- [(5-nitro-l,3,4-thiadiazol-2-yl)methylen]-amino -2-imidazolidinone [540], 2-[(2-methyl-5-nitrothiazol-4-yl)methylene]-malonate and its imidazole analogs [547, 548] have been reported. 

NITRO-2-FURANYL)METHYLENE).AMINO)-2-IMIDAZOLIDINONE see NDYOOO... 

Dimethyl-2-imidazolidinone, 6, 374 Dimethylmaleic anhydride, 187 Dimethyl(methylene)ammonium hahdes,... 

The rather uncommon 4- and 5-imidazolethiols can be made by a dehydration-cyclization of (195), a reaction promoted by formic acid, trimethylsilyl triflate, or triethylamine <87JOC2977>. Similarly, when the 1,2-diamine has a carbonyl function replacing one of the methylene groups the products are 4-imidazolidinones, as in the 2-iminohydantoin (196) synthesis illustrated (Scheme... 

Nifuradene. t-[[(5-Nitro-2-furanyl)methylene]-aminoJ-2-imidazolidinone oxafuradene (rescinded) N F-246 NSC 6470 Renafur. C,H,N404 mol wt 224.17. C... 

The N-monosubstituted oxamic acids were converted to free amines with diphenylcarbodiimide. Treatment of 458 with this reagent in methylene chloride (0°C, 1 hr) produced 7a-methoxyamine 462. After acylation with chloroacetyl chloride (A,N-dimethylaniline, 25 C, 16 hr) amide 463 was isolated in 40% yield. Substance 458 reacts with dicyclohexylcar-bodiimide in a different and unfavorable manner to form imidazolidinone 464 (36%) and amidine 465 (6%). Hydrolysis of the former with p-TSA gave dicyclohexylimidazolidinetrione and 7-oxocephem methyl ester (466). 

Hydroxyphenyl)methylene]-2-thioxo-4-imidazolidinone, H-00485 5-[(2-Hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone, H-00486 5-[(3-Hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone, H-00487... 

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