Hydantoin, 5-Methyl

Among radicals from diazoles, in the imidazole series hydantoin, methyl-hydantoin, and thiohydantoin have given various radicals e.g., 159, differing in degree of protonation, upon radiolysis of aqueous solutions.546 Values of... 

Methoxy-l -methyl-hydantoin-methyl iinid-(4)-oarbonB ure-(5) ainid 2S 1604,... 

Hydantoin, 5,5-diaryl-2,4-dithio-methylation, 5, 444 Hydantoin, 1,3-divinyl-polymers, 1, 280 Hydantoin, 5-methylene-polymers, 1, 280 Hydantoin, 5-phenyl-2-thio-tautomerism, 5, 370 Hydantoin, thio-... 

Condensation of o-phenylenediamine or xV-methyl-o-phenylcne-diamine with alloxan (8) in neutral solution gives the ureides (9) and (10), respectively However, reaction of o-phenylenediamine with 1,3-dimethylalloxan (13) yields quinoxalin-3-one-2-carboxymethyl-amide (14), rather than the dimethyl ureide. Methylation of (9) in acetone in the presence of potassium carbonate gives the spiro-hydantoin (11). 

S ORTHO AND EFFECT AND HAMMETT S (carbon(W)DIOXIDE OR carbon(W)DISULnDE) AND CATALY NOT ACID S HYDANTOIN AND (METHYL OR ETHYL) NOT (VINYL OR PHENYL)... 

The method described serves for the preparation of various 5-substituted or 5,5-disubstituted hydantoins, using appropriate cyanohydrins. With methylethylketone cyanohydrin there was obtained a 75 per cent yield of 5-methyl-5-ethylhydantoin, m.p. i4i-5°-... 

K. Ienaga, K. Nakamura, A. Ishii, T. Taga, Y. Miwa, F. Yoneda, The Stepwise Mammalian Oxidation of the Hydantoin l-Methyl-imidazolidine-2,4-dione into Methylimi-dazolidinetrione via 5-Hydroxy-l-methyl-imidazolidine-2,4-dione , J. Chem. Soc. Perkin Trans. 1 1989, 1153-1156. 

EPA pesticide chemical di methyl hydantoin EPA pesticide chemical Dichloropropylene, 1 EPA pesticide chemical Dichloropropane EPA pesticide chemical EPA pesticide chemical chloroethyl) ether EPA pesticide chemical EPA pesticide chemical EPA pesticide chemical EPA pesticide chemical EPA pesticide chemical EPA pesticide chemical cresol... 

L-Serine methyl ester can be transformed into methyl oxazolidin-2-one-3-carboxylate with phosgene and aqueous potassium carbonate (90TL7407). Some AAs (Gly, Val, Phe) were transformed into their iV-(2-chloroethylcar-bamoyl) derivatives, and these can cyclize into oxazolines (Scheme 24) (83T2255). In boiling water they are transformed into hydantoin derivatives. 

It is well known that isothiocyanates react with a-AAs to give hydantoins, but methyl o-isothiocyanatobenzoate gives a tetrahydroquinazoline derivative (67HCA1440). 

Alkylation of the hydantoin (89-2) from benzaldehyde with ethyl iodide takes place at the imide nitrogen to afford ethitoin (89-3) [93]. In much the same vein, treatment of the hydantoin (89-5) from propiophenone with methyl iodide (89-5) in the presence of a base affords mephenytoin (89-6) [94]. Replacement of the quite acidic imide proton by an aUcyl group is not required for activity the well-known anticonvulsant phenytoin (89-8) consists of simply the hydantoin obtained from benzophenone (89-7) [95] this is often formulated as its sodium salt. 

Trifluoromethyl-substituted aromatic compounds are obtained by reacting methyl arenecar-bodithioates with tetrabutylammonium dihydrogen trifluoride and l,3-dibromo-5.5-dimethyl-hydantoin. The use of /V-bromosuccinimide or A-iodosuccinimide instead of l,3-dibromo-5,5-dimethylhydantoin affords difluoro(methylsulfanyl)methyl-substitutcd aromatics.62... 

An even more convincing argument is provided by the studies (46), results of which are also shown in Fig. 14. Tri-n-butyl amine in dimethyl formamide induces only a slow polymerisation of L-proline NCA whereas the polymerisation of y-ethyl-L-glutamate NCA is very fast under these conditions even if the concentration of the base is reduced by a factor of ten (78, 46). This is a striking observation since proline NCA is an extremely reactive monomer and polymerises very fast on addition of a primary amine. However, addition of 3-methyl hydantoin,... 

However, the exceptionally high capacity of 3-methyl hydantoin to initiate such a polymerisation [see ref. 46)] calls for some further explanations. 

According to Prof. Bamford 3-methyl-hydantoin anion is exceptional in its ability to initiate the polymerisation of N-substituted NCA s in the presence of tertiaty amines. This observation calls for some additional explanation. 

It should be remarked, at this juncture, that Bamford s experiments utilising 3-methyl hydantoin as a co-catalyst do not shed light on the problem of propagation. They have shown, merely, that a proton is required for the simple amine-piropagated polymerisation and, according to his scheme, any proton donor may suffice to produce this result (see however the footnote on p. 44). For example, if his mechanism is correct, sarcosine NCA should not be polymerised by sodium methoxide in a rigorously aprotie medium1, but polymerisation should ensue on... 

Nl - HYDANTOIN, 5.5-DXPHENYL-, and 5-ETHYL-1-METHYL-5-PHENYL8ARBITURIC ACID (1 2)... 

The hydantoins (116 and 117) have been prepared from DL-j8-ferrocenyl-a-alanine and N - ferrocenyl methyl-AT-(a-carbethoxy-benzyl)urea, respectively.68 The Friedel Crafts reaction of ferrocene and 2-pyrroylchloride gave the ketone (118).112,113 The polarographic half-wave potentials of 118 and other related ferrocenes were measured113 and it was concluded that the ferrocene radical was more electropositive than the phenyl radical. 

Early syntheses of SeMet were tedious, non-stereospecific or limited to small-scale preparations. Klosterman and Painter (1947), for example, first reacted 5-((3-bromoethyI)- hydantoin with benzyl selenol to yield y-benzylselenoho-mocysteine. The latter was converted to the sodium salt of DL-selenohomo-cysteine with sodium in liquid ammonia, and reacted with methyl iodide to yield DL-SeMet. Plieninger (1950) obtained DL-SeMet by the reaction of sodium selenomethyl mercaptide with a-amino-y-butyrolactone in an inert solvent at 170°C. A synthesis of DL-SeMet from acrolein was also described (Zdansky, 1968). The first stereospecific synthesis of L-SeMet via esters of tosylated homoserine was reported by Pande et al. (1970). 

A condensation occurs between 5-hydroxymethylfurfural and malonic ester20 and in a similar way, two molecules of malonic ester react with furan 2,5-dialdehyde.88 A condensation product, XXXV, has also been obtained with hydantoin.89 5-Hydroxymethylfurfural and its acetyl derivative undergo the Perkin reaction with sodium acetate and acetic anhydride giving 5-acetoxymethylfuran 2-acrylic acid (XXXVI).70 Similar products of the same reaction are obtained from 5-methyl-furfural71 and 5,5 -diformyl-l,l -furylmethyl ether (XXVII).61,72... 

---