Hydantoin, 5,5’-Dimethyl

CAS 77-71-4 EINECS/ELINCS 201-051-3 Synonyms Dimethylhydantoin 5,5-Dimethyl hydantoin 5,5-Dimethyl-2,4-imidazolidinedione DMH 2,4-Imidazolidinedione, 5,5-dimethyl-Classification Organic compd. 

N,N -Dimethylol-4,5-dihydroxyethyleneurea Dimethyloldihydroxyimidazolidinone. See Dimethyloldihydroxyethyleneurea Dimethylol dimethyl hydantoin 1,3-Dimethylol-5,5-dimethyl hydantoin Dimethylol-5,5-dimethylhydantoin. See DMDM hydantoin Dimethyl oleamine CAS 14727-68-5 28061-69-0 Synonyms N,N-Dimethyloleylamlne Oleyl dimethylamine Classification Tertiary amine Empirical C20H41N... 

Prepared by Spielman (761) from S-indoleglyoxylic add, hydantoin, dimethyl aniline and morpholine. 

Dimethylol dimethyl hydantoin 1,3-Dimethyk>l-5,5-dimethyl hydantoin Dimeth-yk>l-5,5-dimethylhydantoin. See DMDM hydantoin Dimethyl oleamide... 

Solvent variation can gready affect the acidity of hydantoins. Although two different standard states are employed for the piC scale and therefore care must be exercised when comparing absolute acidity constants measured in water and other solvents like dimethyl sulfoxide (DMSO), the huge difference in piC values, eg, 9.0 in water and 15.0 in DMSO (12) in the case of hydantoin itself, indicates that water provides a better stabilization for the hydantoin anion and hence an increased acidity when compared to DMSO. 

The addition proceeds most smoothly with highly functionalized (more polar) steroids as seen in examples by Bernstein and others. The polar reaction conditions pose solubility problems for lipophilic androstane, cholestane and pregnane derivatives. Improved yields can be obtained in some cases by using dimethyl sulfoxide or t-butanol " as solvents and by using sodium A-bromobenzenesulfonamide or l,3-dibromo-5,5-dimethyl hydantoin (available from Arapahoe Chemicals) as a source of positive bromine. The addition of bromo acetate and bromo formate to steroid olefins has been studied to a limited extent. ... 

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). 

For this solid-phase approach, conventional iPrOCH2-functionalized polystyrene resin (Merrifield linker) was employed. After attachment of the requisite substrate, the resin was pre-swollen in a solution of barium(II) hydroxide in N,N-dimethyl-formamide within an appropriate sealed microwave vial. The vial was heated in the microwave cavity for 5 x 2 min cycles (overall 10 min) with the reaction mixture being allowed to cool to room temperature in between irradiation cycles (Scheme 7.50), leading to comparatively modest isolated yields of hydantoins. 

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,... 

Figure 11.16 Decomposition of l.S-Dichloro-S.S-dimethyl-hydantoine in heptane (SI) und tetrachloro carbon (S2). Isothermal DSC-thermograms recorded at 140 C.

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