2-Thio-hydantoin

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-... 

FIGURE 20.21 N-allyl derivatives of hydantoin, thio-hydantoin and dibenzazepine. 

C-nmr data have been recorded and assigned for a great number of hydantoin derivatives (24). As in the case of H-nmr, useful correlations between chemical shifts and electronic parameters have been found. For example, Hammett constants of substituents in the aromatic portion of the molecule correlate weU to chemical shifts of C-5 and C-a in 5-arylmethylenehydantoins (23). Comparison between C-nmr spectra of hydantoins and those of their conjugate bases has been used for the calculation of their piC values (12,25). N-nmr spectra of hydantoins and their thio analogues have been studied (26). The N -nmr chemical shifts show a linear correlation with the frequencies of the N—H stretching vibrations in the infrared spectra. 

N — N — — Imidazole 4,5-di-t-butylimidazole histamine dihydrochloride 2-thio-hydantoin... 

Beispielsweise nimmt bei Merocyaninen mit Rhodanin- und Thio-hydantoin-Ringen die Adsorption an AgBr mit fallender Silberionenkonzentration, also mit steigendem fiAg nicht zu, sondem ab. 

A somewhat different scheme is used for the preparation of an all-aliphatic thio-hydantoin. Thus, reaction of racemic leucine (91-1) with allylisothiocyanate (91-2) leads to the thiourea (91-3). Attack of the anion from treatment of that intermediate with a strong base leads to ring closure and the formation of the imidazoline ring. There is thus obtained the anticonvulsant agent albutoin (91-4) [97]. 

The Ugi-4CR between cyclic ketones, primary amine hydrochlorides, potassium thiocyanate (or selenocyanate), and 2,2-diethoxyethyl isocyanide [91] afforded the spiro 2-thio-(or seleno)hydantoin-4-imines 166. On heating in acetic acid, compounds 166 underwent carbonyl deprotection and cyclization to spiro imidazo[l,5-ajimidazoles 167 (Scheme 2.60). 

Dang, P. and Madan, A.K. (1994) Structure-activity study on anticonvulsant (thio)hydantoins using molecular connectivity indices. J. Chem. Inf. Comput. Sci., 34, 1162-1166. 

Extensive MO calculations for bond lengths and angles of l-phenyl-2-thio-5-carbomethoxymethylhydantoin have been reported.218 He(I) excited photoelectron spectra of hydantoin and 1-methyl-hydantoin are assigned by comparison with the spectrum of succinimide and by INDO/S calculations.219... 

Condensation of urea with carbonyl compounds A rapid and efficient MW-assisted synthesis of hydantoins and thiohydantoins was described by Muccioli et al. [117]. The most straightforward conditions for synthesis of phenytoin are the base-catalyzed condensation using benzil and urea, known as the Biltz synthesis (Eq. 33). MW activation of the Biltz synthesis of phenytoin improved both yield and reaction time. The first step consists in MW activation of the reaction of benzil with (thio)urea the second includes the conversion of the resulting 2-(thio)hydantoin to hydantoin using hydrogen peroxide. When reactions were performed at the same temperature under both reaction conditions, yields were by far better under the action of MW and emphasized the evident specific MW effects. These are perfectly expected when one considers the polar TS involved in the first step (nucleophilic addition of neutral NH2 group on carbonyl moiety). 

Moorthy et al. [32] have synthesized 5-isopropylidiene derivatives of 3-dimethyl-2-thio-hydantoin XXVI, 3-ethyl-2-thio-2,4-oxazoIidinedione XXVII, and 5-benzilidene-3-ethyl rhodanine XXVIII, which are cytotoxic against leukemic cell line in concentration-dependent manner. The results of the trypan blue and MTT assays indicated that the compound XXVIII found to be fivefold to sevenfold more potent than XXVI and XXVII with IC5o<10 pM. XXVIII found to affect DNA replication by inducing a block at S phase on the basis of cell cycle analysis and tritiated thymidine assays. Moreover, the treatment of XXVIII led to increased level of reactive oxygen species (ROS) production and DNA strand breaks. This suggests the activation of apoptosis for induction of cell death. 

S.Phenoxy.2-thi urscil 26. 61. S-Salicyliden-S-thio-hydantoin 86 1 602. 3-BenCT]idenamino.2.4-dioxo-thiazolidin 8711287. 

S-Benzylmercapto-uracil 85, 61. 5-[2-Methoxy-] zyiiden 1-2-thio-hydantoin 86 1 503. 

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