Trihydroxy pyrimidine

Tanner,from infrared spectral work, tentatively concluded that 4,6- and 4,5-dihydroxy- and 4,5,6-trihydroxy-pyrimidines exist in the monooxo forms 117, 118 (X = H), and 118 (X — OH), respectively these conclusions are supported by ultraviolet spectral data and chemical evidence. " 2,4,5,6-Tetrahydroxypyrimidine has been isolated in two forms—dialuric acid and isodialuric acid, usually formulated as 119 and 120, respectively, on the basis of rather convincing chemical evidence [for a review see reference 109(f) cf. reference 178]. Isodialuric acid is converted into dialuric acid by base as would be expected if structures 119 and 120 are correct. On the basis of its infrared spectrum, dialuric acid has been concluded to exist in the tetrahydroxy form, but the correctness of this conclusion appears very doubtful. 

Trifluormethan- -diethylester E2, 369 2-(2,4,6-Trihydroxy-pyrimidin-5-yl)-ethan- -dialkylester XII/1, 515 2-Trimethylammoniono-ethan- XII/1, 356 2-Trimethylammoniono-ethan- -dialkylester-jodid XII/1, 519... 

Pyridazine 3,4-Dimethoxy-6-methyl- -1-oxid E9a, 641 (N02 -> OR) Pyrimidine 5-Isopropyl-trihydroxy-E9b/2, 58 f. (ROOC-CH2-COOR + R-Br/Urea)... 

Trihydroxy-4,5-dimethoxy-9-phenyl-4,5-dihydro-9H- (imidazo-[4/>-d -pyrimidin) 58% d.Th. 

Chlorine derivatives of pyriinido[5,4-d]pyrimidines are readily prepared by the reaction of pyrimido[5,4-rf]pyrimidinols with a mixture of phosphorus pentachloride and phosphoryl chloride. Using this method, 2,4,6,8-tetrachloro- or 2,4,8-trichloropyrimido[5,4-r/]pyrimidines can be obtained in good yields from the corresponding tetrahydroxy- and trihydroxy-substituted starting materials.213... 

A relat pyrimidine, 2,4,5-trihydroxy-6-aminopyrimidine (convicine, isouramil, VI), is also present in vetch [23]. Both divicine and convicine are... 

Examples of cocrystals containing chains, ribbons, and other infinite ID motifs (Scheme 8) include bipyridine dihydroxybenzene, melamine cyanuric acid, bipyridine (fluorinated)dibromobenzene, 2-aminopyridine dicar-boxylic acids, triaminopyrimidine barbituric acid, 2-aminopyrimidine dicarboxylic acid, " 1,2,3-trihydroxy-benzeneihexamethylenetetramine, diols diamines, bis-benzimidazole dicarboxylic acids, and 2-amino-5-nitro-pyrimidine 2-amino-3-nitropyridine." ... 

The barbiturate structure resembles that of hydantoins and dialkyl acetyl urea derivatives which are also neuroactive agents (Fig. 4.8). It is clear that the dialkyl substitution at position 5 of barbiturates is essential for their pharmacological activity. Also, if one or two hydrogens are left at position 5 of the barbiturate, the barbiturate will be converted to the trihydroxy pyrimidine derivative, as discussed earlier. 

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