Pyrimidine, also known as 1,3-diazobenzene, is a heterocyclic compound with the chemical formula C4H4N2. Pyrimidine is formed by substituting 2 nitrogen atoms for 2 carbons in the meta-position of benzene. It is a diazine and retains its aromaticity. Derivatives of pyrimidine widely exist in organic macromolecular nucleic acids, and many drugs also contain pyrimidine rings. In nucleic acids, three nucleobases are pyrimidine derivatives: cytosine, thymine and uracil. There are a variety of pyrimidine-containing drugs on the market, most of which are kinase inhibitors.
Oxazolidines are five-membered ring compounds consisting of three carbons, nitrogen and oxygen. Oxygen and nitrogen are in the 1 and 3 positions, respectively. Oxazolidine is in general yellow or slightly yellow, alkaline liquid or solid, easily hydrolyzed by water or alcohol. It is insoluble in water (or hydrolyzed); soluble in benzene and chloroform. Oxazolidine derivatives are five-membered cyclic compounds containing at least one oxygen and nitrogen in their molecular structure. Oxazolidine derivatives are known to possess various therapeutic activities, such as anticancer and antibiotic properties.