Uracils hydantoins

Supplement 1936 3458-3793 Picrolonic acid, 51. Hydantoin, 242. Uracil, 312. Indigo, 416. Barbituric j acid, 467. Alloxan, 500. ... 

Der Uracil-Ring wird in 1,3,10-Trimethyl-flavinium-perchlorat durch Reduktion mit Natriumboranat in Wasser zu dem Hydantoin-Ring umgelagert3. 

Hydantoin, the cyclic form of hydantoic acid, was detected in the Murchison meteorite and also as a product of polymerisation of HCN (Ferris et al 1974). The yields obtained (based on cyanoacetaldehyde) were 18% for cytosine-N -acetic acid, but only 1.8% for the corresponding uracil derivative (1 mM cyanoacetaldehyde and 2 M hydantoic acid were allowed to react at around 373 K). 

Many N3 substituted (Ni, according to the uracil numbering system) orotic acids (XVII), prepared by the treatment of the appropriate hydantoins with sodium hydroxide, were reported to be useful as antiviral drugs [216]. 

We have now inaugurated in the Sheffield Chemical Laboratory an extended research dealing with the application of catalytic methods of reduction and oxidation to pyrimidine, purine, hydantoin and glyoxaline compounds, and in this paper, the first of our series, we record the results obtained by direct reduction of the pyrimidine uracil with colloidal platinum. 

From both a biochemical and a synthetical point of view the synthesis of hydrogenated uracils by direct reduction of the pyrimidine ring is a reaction of considerable importance. These reduced uracils bear a similar relationship to /3-aminoacids as the hydantoins do to a-aminoacids. A practical method of reducing uracil combinations, therefore, opens up a new method of synthesizing representatives of this important class of... 

Ozonolysis of cellular substances, such as uracil and thymine derivatives, is of special interest. Ozonolysis of aqueous solutions of uracils leads to ring cleavage and subsequent ring contraction forming 5-hydroxy-hydantoins (89CL723 90JOC1396) (Scheme 158). 

Treatment of 5-acetoxy-6-(acetoxymethyl)uracils (40) with very dilute sodium hydroxide solution affords hydantoins (42) via the exocyclic methylene intermediate 41.86... 

The cyclic diamides such as Hydantoin and Uracil are normally not soluble in carbon tetrachloride nor deuterochloroform unless one or both of the nitrogen atoms are substituted by an aliphatic group. The compounds are usually readily soluble in Polysol, DMSO-d6, acetone and trifluoroacetic acid. 

Natural cyclic amides such as 5,6-dihydrouracil, uracil and 5,6-dihydrothymine as well as hydantoin, 5-methylhydantoin and 5-hydroxymethylhydantoin are effective inducers for enzyme biosynthesis (for a more detailed review on induction experiments see reference13 ). In some cases, the dihydropyrimidinase (D-hydantoinase) is associated with an N-carbamoyl-D-amino acid amidohydrolase (D-carbamoylase) and a hydantoin racemase1301. The previously proposed identity of the D-N-carbamoylase with the p-ureidopropionase (E. C. 3.5.1.6), which was assumed to be responsible for the hydrolysis of N-carbamoyl-P-alanine (see Fig. 12.4-7) 131-351 is no longer valid since the investigations of Ogawa et al. on different aerobic bacteria showed that the... 

Supplement 1936 3468-3793 Picrolonic acid, 61. Hydantoin, 242. i Uracil, 312. Hidigo, 416. Barbituric 1 acid, 467. AUoxan, 500. 1... 

Phenyl- and 1-naphthylisocyanate react exothermically, to give compounds which were first thought to be uracil derivatives (43), but finally were identified as hydantoins. After hydrolysis of the vinyllead grouping the lead-free l,3-diaryl-5-benzylidene hydantoin is formed. The following pathway is proposed and is well supported by different arguments (45) ... 

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

Clostridium uradlicum was specific for dihydrouracil, while the calf liver enzyme cleaved not only dihydrouracil but dihydrothymine and hydantoin as well (4 1). In regard to differences in specificity, it is of interest that the bacterial enzyme was an induced enzyme sjmthesized only when uracil was present in substrate amounts in the growth medium 4 5). 

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