5-Acetyl-4,6-dimethyl-1,2,3,4-tetrahydropyrimidin-2-one

The title compound, C₈H₁₂N₂O₂, belongs to the class of 5-substituted 1,2,3,4-tetrahydro­pyrimidin-2-ones, which exhibit a wide spectrum of biological activities. The conformation of the tetrahydropyrimidine ring is that of a distorted boat. In the crystal structure, N—H...O hydrogen bonds form molecular dimers and also link these dimers into chains along the c axis of the unit cell.

Ethyl 4,6-dimethyl-2-thioxo-1,2,3,4-tetrahydro­pyrimidine-5-carboxyl­ate

The title compound, C₉H₁₄N₂O₂S, belongs to a group of esters of 2-oxo- and 2-thioxo-1,2,3,4-tetrahydro­pyrimidine-5-carboxylic acids, which exhibit a wide spectrum of biological activities. The conformation of the pyrimidine ring is a distorted boat. In the crystal structure, hydrogen-bonded centrosymmetric dimers are formed via intermolecular N—H...S hydrogen bonds. The dimers are linked by inter­molecular N—H...O hydrogen bonds to form a two-dimensional network.

1-[4,5-Bis(hydroxy­meth­yl)-1,2,3-triazol-1-ylmeth­yl]thymine

The title compound, C₁₀H₁₃N₅O₄, can be classed as both a homo-C-nucleoside and an analogue of nucleosides possessing a 1,2,3-triazole ring instead of a furan­ose residue, some derivatives of which are potent antiviral agents. The mutual mol­ecular arrangement of the five- and six-membered cyclic residues, as well as their disposition relative to the bridging –CH₂– group, has been analyzed. In the crystal structure, inter­molecular N—H...O and O—H...O hydrogen bonds form an infinite three-dimensional mol­ecular network.