The asymmetric unit of the title compound, C(12)H(14)N(2)O(4), contains two independent mol-ecules. In one independent mol-ecule, the furanyl fragment is rotationally disordered between two orientations in a 0.625 (6):0.375 (6) ratio. In the crystal, inter-molecular pyrimidine-pyrimidinone N-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric tetra-mers, which are further associated int...

Heterodimeric interstrand cross-linked DNA was constructed by the "bis-click" reaction carried out on preformed oligonucleotide duplexes with the bis-azide 1. For this, alkynylated 8-aza-7-deazapurine or corresponding 5-substituted pyrimidine nucleosides were synthesized. Cross-linking resulted in chemoselective formation of heterodimeric duplexes while homodimers were suppressed. For product i...

2,4-Dichloro-, 4,6-dichloro-, 2,4,6-trichloroand tetrachloropyrimidine undergo nucleophilic displacements by 4-(dimethylamino)pyridine to give (pyrimidine-2,4-diyl)-1,1’-bis[4-(dimethylamino)pyridinium] dichloride, (pyrimidine-4,6-diyl)-1,1’-bis[4-(dimethylamino)-pyridinium] dichloride, (pyrimidine-2,4,6-triyl)-1,1’,1”-tris[4-(dimethylamino)pyridinium] trichloride, and (5chloropyrimidine-2,4,6-...

In the title compound, C(18)H(21)N(3)O(6), a pyrimidine derivative, the dihedral angle between the benzene and pyrimidine rings is 52.26 (12)°. The carboxyl-ate unit is twisted with respect to the pyrimidine ring, making a dihedral angle of 12.33 (7)°. In the crystal, mol-ecules are linked by a pair of O-H⋯O hydrogen bonds, forming an inversion dimer. The dimers are stacked into columns along t...

The title compound, C11H9N5OS2, a 1-thio-phen-2-yl-methyl-ene-amino-pyrimidine derivative, displays an essentially planar C-NH2 group. The conformation across the N=C bond linking the pyrimidine and thienyl groups is E. The pyrimidine and thienyl ring systems subtend an inter-planar angle of 42.72 (5)°. In the crystal, mol-ecules are linked by N-H⋯Nnitrile and N-H⋯O=C hydrogen bonds, forming ch...

Tissue culture cells of Drosophila melanogaster were given various doses of ultraviolet light. The results indicate that Drosophila cells do have a dark-repair excision mechanism which is not sensitive to caffeine. Pyrimidine dimers were destroyed by photoreactivating illumination in these cells and this destruction probably represents monomerization of the pyrimidine dimers.

The crucial role of photosensitizer@DNA complexation in the formation of cyclobutane pyrimidine dimers (CPDs) has been demonstrated using femtosecond and nanosecond transient absorption and emission measurements in combination with in vitro DNA damage assays. This finding opens the door to re-evaluate the mechanisms involved in CPDs photosensitized by other chemicals.