Benz pyrimidine

Reaction of 2,3-isopropylidene-j3-D-ribofuranosylamine with iV-2,4-dinitro-phenyl-3-benzoyl-pyridinium chloride yielded the pyridinium nucleoside analogue (8). Glycosyl isocyanides yield formamidines with amines, which can be cyclized to nucleoside analogues in appropriate cases thus, methyl anthrani-late in presence of mercuric chloride yields the benz-pyrimidine derivative (9). Standard methods have been used to prepare l-(6-deoxy- 3-D-allo- and -ot-L-talo-furanosyl) uracil and 9-0[-L-rhamnopyranosyl-2-alkylthio-adenines. ... 

The halogen atom in benz-chloro substituted quinazolines is very stable (as in chlorobenzene), whereas the halogen atoms in positions 2 and 4 show the enhanced reactivity observed with halogen atoms on carbon atoms placed a and y to heterocyclic ring nitrogens. The chlorine atom in position 4 is more reactive than in position 2, and this property has been used to introduce two different substituents in the pyrimidine ring. ... 

FIGURE 3. Thiocarbonyl ligands involved in Tables 20-25 (a) pyridine-2-thione, (b) pyridine-4-thione, (c) pyrimidine-2-thione, (d) l,3-imidazoline-2-thione, (e) benz-l,3-imidazoline-2-thione, (f) l,3-imidazolidine-2-thione, (g) l,3-thiazoline-2-thione, (h) benz-1,3-thiazoline-2-thione, (i) 1,3-thiazolidine-2-thione, (j) 1,2,4-triazoline-3(5)-thione, (k) 1,2,3,4-tetrazoline-5-thione... 

Apart from acid derivatives, aldehydes and ketones are also versatile reagents. The (5-benz-y]ideneamino)pyrimidine which is formed initially undergoes ring closure on reaction with an oxidizing agent such as iron(III) chloride or iron(III) oxide. ... 

Reactions of 2-formyl-galactal, presented as an unsaturated sugar derivative with push-pull functionalization, with guanidinium and amidinium salts, respectively were carried out imder basic conditions to furnish the substituted 5-( 1,2,4-tri-O-benzyl-D-lyxo- l,2,3,4-tetrahydroxy-butyl)pyrimidines 92 (Fig. 16). Treatment of the 2-formyl pentose glycals with 2-aminobenzimid-azole and 3-amino-1,2,4-triazole, respectively afforded 3-(l,2,4-tri-0-benz-yl-D-lyxo-l,2,3,4-tetrahydroxy-butyl)benzo[4,5]imidazo[l,2-a]pyrimidine 94... 

Ion cyclotron resonance studies confirm earlier conclusions based on photoelectron spectroscopic data that pyridine-4-thione exists mainly as the thiol tautomer in the gas phase. The potential of this technique for measuring tautomeric equilibrium constants in the gas phase is discussed. Alkylation of ambident anions of the type [N—C—S] , e.g. pyridine-2-thione, in the presence of a phase-transfer catalyst (Bu4N Br") leads exclusively to the, S-alkylated products. Yields are generally superior to those obtained by more conventional methods, and easier experimental work-up procedures are claimed for a variety of systems, including pyridine-2-thione, pyrimidine-2-thione, and benz-oxazoline-2-thione. Energies and Alkylations of Tautomeric Heterocyclic... 

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