Pyrimidine-4-carboxylic acid

4′-Hydroxy­biphenyl-4-carboxylic acid

The title compound, C(13)H(10)O(3), has potential oxygen donor and acceptor sites. Inter-molecular hydrogen bonding between neighboring carboxyl-ate groups leads to the formation of hydrogen-bonded dimers [graph-set motif R(2) (2)(8)]. A second hydrogen-bonding inter-action between the hydr-oxy groups generates a chain and extends the structure into a lamellar layer. One of the benzene rings is...

Pyrimidine-4-carb­oxy­lic acid

The crystal structure of the title compound, C5H4N2O2, is built of acid mol-ecules located on a mirror plane. They form sheets stacked along the b-axis direction. The mol-ecules inter-act via O-H⋯N hydrogen bonds, forming [001] chains, and weak van der Waals inter-actions.

5-Methyl­isoxazole-4-carboxylic acid

In the title compound, C(5)H(5)NO(3), the mol-ecule lies on a crystallographic mirror plane with one half-mol-ecule in the asymmetric unit. An intramolecular C-H⋯O inter-action is present. In the crystal, strong inter-molecular O-H⋯N hydrogen bonds result in the formation of a linear chain structure along [100], and there are also weak C-H⋯O hydrogen bonds between the chains which help to stabi...

6-Fluoro-4-oxochroman-2-carboxylic acid

The title compound, C(10)H(7)FO(4), is an inter-mediate in the synthesis of the drug Fidarestat, (2S,4S)-2-aminoformyl-6-fluoro-spiro[chroman-4,4'-imidazolidine]-2',5'-dione. The di-hydro-pyran-one ring adopts an envelope conformation with the asymmetric C atom in the flap position. In the crystal, the mol-ecules are linked into zigzag chains along [100] by O-H⋯O hydrogen bonds and C-H⋯π inter-...

On the oxidation of D-1, 3-thiazane-4-carboxylic acid (D-tetrahydro-1,3-thiazine-4-carboxylic acid).