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Uracils nitro

Uracil, 5-methoxy-6-methoxymethyl-2-thio-synthesis, 3, 134 Uracil, 1-methyl-aminolysis, 3, 91 synthesis, 3, 110 Uracil, l-methyl-5,6-dihydro-synthesis, 3, 110 Uracil, 6-methyl-3-phenyl-synthesis, 3, 110 Uracil, 3-methyi-2-thio-synthesis, 3, 112 Uracil, 6-methyl-2-thio-oxidation, 3, 94 Uracil, 5-nitro-... [Pg.919]

Diazo-4>iso-nitrosomethyl-uracil, Nitro Derivotive. See under Diazouracil and Derivatives... [Pg.80]

Later, a completely different and more convenient synthesis of riboflavin and analogues was developed (34). It consists of the nitrosative cyclization of 6-(A/-D-ribityl-3,4-xyhdino)uracil (18), obtained from the condensation of A/-D-ribityl-3,4-xyhdine (11) and 6-chlorouracil (19), with excess sodium nitrite in acetic acid, or the cyclization of (18) with potassium nitrate in acetic in the presence of sulfuric acid, to give riboflavin-5-oxide (20) in high yield. Reduction with sodium dithionite gives (1). In another synthesis, 5-nitro-6-(A/-D-ribityl-3,4-xyhdino) uracil (21), prepared in situ from the condensation of 6-chloro-5-nitrouracil (22) with A/-D-ribityl-3,4-xyhdine (11), was hydrogenated over palladium on charcoal in acetic acid. The filtrate included 5-amino-6-(A/-D-ribityl-3,4-xyhdino)uracil (23) and was maintained at room temperature to precipitate (1) by autoxidation (35). These two pathways are suitable for the preparation of riboflavin analogues possessing several substituents (Fig. 4). [Pg.77]

It may be said in conclusion that the reactivity of position 5 (i.e., 6 of the triazine ring) is similar to that of uracil. The only difference seems to be in the failure to prepare 5-nitro-6-azauracil although this reaction proceeds readily with uracil. [Pg.231]

C9H9N309-H20 5-Nitro-l-(/ -D-ribosyluronic acid)uracil, monohydrate (NRURAM11)140... [Pg.274]

Pd(0)-catalyzed substitution reaction, a novel, mild reduction of a-nitro ester to an amino acid ester with TiCl3, and an improved procedure for uracil ring formation. [Pg.145]

The synthesis of 3-nitro-l-substituted uracil derivatives 30 can readily be performed with trifluoroacetic nitric anhydride, and this procedure is used in nucleoside chemistry to convert the uracil 3-nitrogen to a good leaving group <1995JA3665, 1997JOC1547, 20020L1827>. [Pg.126]

OCH3, SH, NH2, CHg, or COOH,205 adenine-thymine base pair171,175,184, 185 and its cationic and anionic forms209 (for the charge densities at C-5 and C-6 positions in uracil, thymine, 5-amino- 5-nitro- and 6-methyl-uracil, 6-azathymine and orotic acid, see refs. 187, 188) it-HMO + a-Del Re calculations on uracil,369,397 5-fluoro- and 5-bromouracil,397 5,6-dihydrouracil and its anionic form369 n-SCF MO + a-Del Re... [Pg.274]

An intramolecular Mannich-type cyclization of l,3-dimethyl-6-(2-aminophenylthio)uracil (120) has been utilized for the synthesis of 5, 6-dihydropyrimido[4,5-b][ 1,5]benzothiazepine-2,4( 1H,3//)-diones (121) this synthesis was realized by reaction of 120 with an excess of formaldehyde, benzaldehyde, or p-nitro- or p-methoxybenzaldehyde in chloroform in the presence of a catalytic amount of p-toluenesulfonic acid under reflux for 4-10 hours. The thiazepine cyclization using aliphatic aldehydes other than formaldehyde did not give satisfactory results. In these cases the reaction resulted in the formation of a dimeric product that probably... [Pg.86]

The studies of Levene and LaForge60 on the nitration of uridine have since been re-investigated. It had been reported, several decades ago, that treatment of uridine with nitric acid produced a Nitro-Uridin-Carbon-saure which was stated to be a dimer containing an anhydro typeof linkage (positions unspecified) between two nucleoside residues.60 According to an abstract,269 this compound has now been identified as the monomeric 5-ni-tro-l-(/8-D-ribosyluronic acid)uracil (CXXII) this was converted to the isopropyl ester and the 2,3-O-isopropylidene acetal thereof. Nitration of the pyrimidine moiety of uridine without oxidation of the 4-(hydroxy-... [Pg.358]

Ethyl nitroacetate reacts with urea or its JV-mono-substituted derivatives in the presence of- triethyl orthoformate to produce the ureidomethylene derivatives 123. These can be easily cyclized by sodium alkoxide to 5-nitro-uracil derivatives (124)118 (Scheme 24). Use of A/,iV -dimethylurea leads... [Pg.143]

In the only neutron diffraction study of a (heavily modified) nucleoside, 5-nitro-1 -09-D-ribosyluronic acid)-uracil monohydrate [466], there is a complicated scheme of hydrogen bonds which involves two-center and three-center C-H 0... [Pg.157]

Table 10.1. CH 0 hydrogen bonds observed in the crystal structure of 5-nitro-l-(/ -D-ribosyl-uronic acid)-uracil monohydrate (NRURAM11) by neutron diffraction at 80 K [466]... Table 10.1. CH 0 hydrogen bonds observed in the crystal structure of 5-nitro-l-(/ -D-ribosyl-uronic acid)-uracil monohydrate (NRURAM11) by neutron diffraction at 80 K [466]...
Ihkusagawa F, Koetzle TF, Srikrishnan T, Parthasarathy R (1979) C-H—O interactions and stacking of water molecules between pyrimidine bases in 5-nitro-l-G0-D-ribosyluronic ac-id)-uracil monohydrate, [ 1 -(5-nitro-2,4-dioxopyrimidinyl)-/ -ribofuranoic acid monohydrate] a neutron diffraction study at 80 K. Acta Cryst B 35 1388 -1394... [Pg.529]

NRURAM20. 5-Nitro-1 -(/S-D-ribosyluronic acid)-uracil monohydrate (CjHj Oj, HzO). Srikrishnan T, Parthasarathy R (1978) Acta Crystallogr, Sect B 34 1363... [Pg.559]

Of 2,4-dialkoxypyrimidines, only 2,4di-tert-butoxy pyrimidine19 and 5-nitro-2,4-dimethoxypyrimidine20 failed to react in the normal Hilbert-Johnson fashion, and anomalous O-2-glycosyl derivatives have been obtained21 with a 2,4-dialkoxypyrimidine substituted in position 6, namely, with 2,4-diethoxy-6-meth3dpyrimidine anomeric 2-tetra-0-acetyl-D-glucopyranosyloxy-4-ethoxy-6-methylpyrimidines (18) resulted. Unsuccessful attempts to synthesize an X-l-ribo-furanosyl derivative of orotic acid (uracil-6 carboxylic acid) have been reported.22... [Pg.121]


See other pages where Uracils nitro is mentioned: [Pg.104]    [Pg.760]    [Pg.229]    [Pg.227]    [Pg.16]    [Pg.1]    [Pg.406]    [Pg.252]    [Pg.247]    [Pg.86]    [Pg.197]    [Pg.808]    [Pg.104]    [Pg.270]    [Pg.229]    [Pg.760]    [Pg.434]    [Pg.255]    [Pg.545]    [Pg.360]    [Pg.249]    [Pg.273]    [Pg.254]   
See also in sourсe #XX -- [ Pg.372 ]

See also in sourсe #XX -- [ Pg.372 ]




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1- uracil 5-nitro-, preparation

Ribosyluronic acid uracil, 5-nitro

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