Pyrimidines, 5-containing

This has been attributed to the self-condensation reactions of these compounds,e.g., acetylacetaldehyde yields s-triacetylbenzene.° Hi. Ethoxymethylene compouTids. Ethoxymethyleneacetoacetates and ethoxymethyleneacetylacetones have been used to prepare pyrido[2,3-d]pyrimidines containing 6-ethoxycarbonyl or 6-acetyl... 

Inspired by its natural function, RibA has been applied in a multienzymatic commercial process for the production of different purine or pyrimidine containing deoxyribonucleosides such as (115) in good yield (Figure 10.42) [184,185]. 

Using a triazole-/pyrimidine-containing hybrid ligand, terminally coordinated in a thiocyanate-bridged copper(II) dimer, Haasnoot et al. reported250 the structure of the f3 isomer of complex (288), revealing that the Cu-SCN distance is relatively short compared to other Cu-SCN... 

A series of antimicrobial pyrazolo[3,4-<7]pyrimidines containing 8-(trifluoromethyl)quinoline have been synthesized from 5-amino-1-[8-... 

The synthesis of some novel acyclonucleosides involving pyrrolo[2,3-c]pyridazine and a 4-hydroxybutyl side chain has been reported <00H(53)5>. New pyrrolo[2,3-selective inhibitors of lck (an src-family tyrosine kinase), have been synthesized and tested <00BMCL2171>. 

The object of this study is to develop new photoresists for deep-UV lithography, by using the reversible photoreaction of pyrimidine bases (17-19). Applicability of pyrimidine containing polymers to both negative and positive type photoresists is due to this photoreversible reaction in which cyclobutane dimers are either formed or cleaved depending on the exposure wavelength (Scheme 2). 

Davis KA, Lin Y, Abrams B et al (1998) Staining of a cell surface human CD4 with 2 F-pyrimidine-containing RNA aptamers for flow cytometry. Nucleic Acids Res 26 3915-3924... 

FIGURE 8-23 H-DNA. (a) A sequence of alternating and C residues can be considered a mirror repeat centered about a central T or C. (b) These sequences form an unusual structure in which the strands in one half of the mirror repeat are separated and the pyrimidine-containing strand (alternating and C residues) folds back on the other half of the repeat to form a triple helix. The purine strand (alternating A and G residues) is left unpaired. This structure produces a sharp bend in the DNA. 

Special properties may be observed for palindromes containing homopurine tracts in one strand, and therefore homopyrimidine tracts in the other. If two identical palindromes of this type occur close together it is possible that die pyrimidine-containing strand of one can join with a hairpin... 

Pancreatic ribonudease cleaves only to the right of a pyrimidine-containing nudeotide... 

Tetrahydro-4-oxo-4//-pyrido[l,2-a] pyrimidines contain an active methylene group in position 9, which permits versatile transformations.148... 

The Bohlmann band appearing between 2650 and 2800 cm-1 in the IR spectra indicated that the unsubstituted perhydropyrido[l,2-n]pyrimidines contain the two rings in trans anellation.238,276,277... 

After modification of lead compound 12, it was found that pyrimidines containing the 3-methylindazole heterocycle and methylated at the C-4 amino nitrogen possessed both good in vitro and cross-species pharmacokinetic profiles. The replacement of the 3,4,5-trimethoxy aniline with a 3-aminobenzenesulfonamide led to comparable potencies. However, significant inhibition (/C50 < 10 pM) was observed against a number of cytochrome (CYP) P450 isozymes, presumably resulting from... 

Giindisch, D., Kampchen, T, Schwarz, S., Seitz, G., Siegl, I, and Wegge, T. 2002. Syntheses and evaluation of pyridazine and pyrimidine containing bioisosteres of ( )-pyrido[3.4-b]homotropane and pyrido-[3.4-b]tropane as novel nAChR ligands. 5 oorgATerf C/2em 10, 1-9. 

Accordingly, uracil-/3-enamino ester, after treatment with dihalotriphe-nylphosphorane (via iminophosphorane), gives, with isocyanates in a normal kind of pyrimidine annullation (90LA901), pyrimido[4,5-alkoxy group capable of several subsequent reactions (88S919) (Scheme 56). 

Tricyclic-fused pyrimidines containing sulfur atoms are accessible from various uracil derivatives. 10-Thiaisoalloxazines are synthesized starting from 6-(o-amino-phenylthio)uracils after diazotization, azide exchange,... 

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