6-Chloro-N4-methyl-N4-phenylpyrimidine-4,5-diamine

6-Chloro-N 4-methyl-N 4-phenyl­pyrimidine-4,5-diamine

In the title compound, C(11)H(11)ClN(4), the dihedral angle between the aromatic rings is 66.47 (8)°. In the crystal, mol-ecules are linked by N-H⋯N hydrogen bonds, generating C(5) chains propagating in [010]. Slipped aromatic π-π stacking between centrosymmetrically related pairs of pyrim-idine rings also occurs [centroid-centroid separation = 3.7634 (12)Å and slippage = 1.715 Å].

ENANO n4 ULTIMO.qxd

Movable (n4) Configurations

An (nk) configuration is a collection of points and straight lines, usually in the Euclidean plane, so that each point lies on k lines and each line passes through k points; such a configuration will be called symmetric if it possesses non-trivial geometric symmetry. Although examples of symmetric (n3) configurations with continuous parameters are known, to this point, all known connected infin...

N4-amino-acid derivatives of 6-azacytidine: structure-activity relationship.

Several N4-derivatives of 6-azacytidine were synthesized using of Vorbrüggen's condensation method. Their antiviral activity with respect to the adenovirus serotypes 2 and 5 in Hep-2 cells culture was studied and primary specific activity was determined. Correlation between chemical structure of new 6-azacytidine derivatives and their biological properties is discussed.

Priestley duality for N4-lattices

We present a new Priestley-style topological duality for bounded N4-lattices, which are the algebraic counterpart of paraconsistent Nelson logic. Our duality differs from the existing one, due to Odintsov, in that we only rely on Esakia duality for Heyting algebras and not on the duality for De Morgan algebras of Cornish and Fowler. A major advantage of our approach is that for our topological ...