5- Diazouracil

The photoelimination of nitrogen from diazo compounds provides a simple and versatile route for the generation of carbenes, and in certain instances, insertion reactions of carbenes can be employed in the synthesis of heterocycles. Carbenes are believed to be involved at least in part in the photochemically induced conversion of N,N-diethyldiazoacetamide (439) into the y-lactam 440 and the /Mactam 441,365 and a similar approach has been successfully employed in the synthesis of a carbapen-2-em366 and of 7-methylcephalosporin analogues.367 Carbene insertion of a different type has been observed on irradiation of the 6-anilino-5-diazouracils 442 to give the indolo[2,3-d]pyrimidines 443.368 Ring contractions in heterocycles... 

This pyrimidine inhibits cell division in bacteria and yeast [319], as well as cell growth in tissue culture [320]. For example, 5-diazouracil possesses signifi-... 

Quantitative evaluation of 5-diazouracil against Walker 256 carcinosarcoma, Ehrlich ascites carcinoma, C3H-FX lymphoma and other tumour systems has been studied and detailed results in comparison with other standard active agents have been reported [332]. 

Substituted azojuracils — The coupling of 5-diazouracil (XXXIX) with certain aminonaphthalene derivatives yielded a number of 5-(4-substituted amino-l-naphthylazo)uracils (XL) which exhibit high schistosomicidal activity against Schistosoma mansoni [334—336]. Compounds of this type were selected from among 500 azo-substituted-heterocyclic compounds after extensive studies in experimental animals [334]. 

QinTOuraci and Derivatives 5-Diazouracil 5-Diazo-2,4-pyrimidinediol or 5-Diazo-4-hydroxy-2(1 H)-pyrimidinone (called 5-Diazo-uracil 5-Diazo-2.4-dioxo-tetrahydro-pyrimidin or 5"Diazo-2.4-dioxy-pyriinidin in Ger),... 

Diazouracil Ethyl Ether (called 5-Diazo-uracil-athyl-ather in Ger), ... 

Diazouracil and derivs 5 D1180—D1181 5 -diazouracil-4-carboxylic acid 5 D1181 5-diazouracil ethyl ether 5 D1181 5-diazo-4-isonitrosomethyl-uracil 5 D1180... 

SYNS 5-DlAZOPYRIMIDINE-2,4(3H)-DIONE 5-DIAZO-2,4(lH,3H)-PYRLMIDINEDIONE 5-DIAZOURACIL 2,4-DIOSSI-5-DIAZOPIRIMIDINA (ITALIAN) 2,6-DIOXO-5-DIAZOPYRIMIDINE DU NSC-23519 (l,2,3)OXADIAZOLO(5,4-d)PYRIMIDIN-5(4H)-ONE... 

N 35.89% exists in two forms ruby-red pits (from w), or yel crysts (from w), mp - explodes when heated on a Pt foil. The red form is obtd from 5-aminouracil NaN02 under cooling, or from 5-diazouracil ethyl ether by hydrolyzing with cold 1% KOH and carefully adding HCl to the K salt. The yel form is obtd by heating 5-diazouracil ethyl ether with water or by long standing of 5-diazouracilcarboxylic acid at RT... 

Diazouracil-4-carboxylic Acid [called 5-Diazo-uracil carbonsaure (4) 5-Diazo-2 6-dioxo-tetrahydropyrimidin-carbonsaure-(4) or 5-Diazo-2.6-.dioxy-pyrimidin-carbonsaure-(4) in GerJ, ... 

Both photolysis and thermolysis of 5-diazouracils 132 result in the formation of formal aromatic C—H insertion products, the corresponding in-dolo[2,3-d]pyridines 133, in good yields (77H1911). 

Whereas the position of the valence equilibrium is of course not affected by the method of carbene generation, a specific disadvantage of the thermal procedure is the possibility of thermally induced structural isomerization of the diazocarbonyl compound itself or of the initially formed norcaradiene a case in point was found when 5-diazouracil or 5-diazo-3-methyluracil were thermally decomposed in benzene. ... 

Andrae U, Schwarz LR. 1981. Induction of DNA repair synthesis in isolated rat hepatocytes by 5-diazouracil and other DNA damaging compounds. Cancer Lett 13 187-193. 

Diazouracil forms a 1,6-dihydro hydrate in water, and a methanolate (325) in methanol... 

Photolytic conversion of the alcoholates of 5-diazouracil (238) into the corresponding imidazolecarboxylates (239) is very slow in neutral solution ca. 10— 15% conversion after 20 h) but is complete in 4—5 h when performed in a solution that is saturated with hydrogen chloride (Scheme 94). Triazoles (241) are formed by acid-catalysed rearrangement of the N-amino-barbituric acids (240 X = O or S) (Scheme 95). ... 

Recent studies on the reaction of 1,2,3-triazoles with glycosyl halides have shown promise in the preparation of glycosyltriazoles (Eq. 26). The use of 5-diazouracils (e.g., 4.2-6) has been shown to be an important approach (Eq. 27) with many examples and excellent yields. El Khadem s laboratory has provided several examples of 2-aryl- derivatives from the osatriazoles (Eq. 28). The extent of interest in this field is illustrated by the publication of an undergraduate laboratory experiment based on the conversion of sucrose to 2-phenyl-l,2,3-triazole-4-carboxylic acid. ... 

Following are some typical examples where both diazotization and coupling reactions take place in succession to yield medicinal important compounds, such as Phenyl-azo-p-naph-thol 5-Diazouracil and Dimethyl-p-phenylenediamine. 

The 5-amino uracil interacts with nitrous acid (generated from sodium nitrite and hydrochloric acid) at 0-5°C to produce one mole of 5-diazouracil and two moles of water. 

The crude product, 5-diazouracil is obtained as crystals mp 195-196°C to the extent of... 

How would you explain the acid reactions of 5-diazouracil that essentially contains four N-atoms of which two embedded in the ring and remaining two as the side-chain ... 

What are vital salient features of 5-diazouracil that make it a potential candidate in cancer research ... 

The chemistry and biological significance of nitric oxide continue to attract great interest. In particular, efforts have been targeted at effective methods for the detection and quantification of this molecule. Walton and Park have reported preliminary results for the use of diazo ketones as spin traps for nitric oxide. 2-Diazocycloheptanone was found to trap nitric oxide, producing the (Z)-iminoxyl radical as the major product, which could be detected by the EPR spectrum obtained from a solution of the spin trap in f-butylbenzene. However, 5-diazouracil was found to be ineffective as a spin trap. 

Carbon f Water 1,2,3-Triazole from 5-diazouracil ring 248. 0, . . N CONHj NN4>C Q)... 

Azopyrimidines of Type 2,—Behrend and Emert showed that 5-amino derivatives of uracil (5-amino-6-methyluracil and 5-aminouracil-6-car-boxylic acid) could be diazotized. Angeli diazotized 5-aminouracil itself and thus obtained 5-diazouracil which was also secured by Behrend and Emert in the decarboxylation of diazotized 5-aminouracil-6-carboxylic acid. From the analyses of these diazopyrimidines Behrend and Emert provisionally proposed the stmctures XII, XIII, and XIV, respectively. 

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