Brown, Desmond J. et al. published their research in Australian Journal of Chemistry in 1981 | CAS: 75833-38-4

Unfused heterobicycles as amplifiers of phleomycin. II. Some 2,4′-, 4,5′- and 5,5′-bipyrimidines was written by Brown, Desmond J.;Cowden, William B.;Strekowski, Lucjan. And the article was included in Australian Journal of Chemistry in 1981.Quality Control of 2-Chloropyrimidine-4-carbonitrile This article mentions the following:

Methoxy, methylthio, dimethylamino, 灏?dimethylaminoethylamino, and 灏?dimethylaminoethylthio substituted 2,4′-, 4,5′- and 5,5′-bipyrimidines were prepared Thus, the pyrimidine I (R = Cl, R¹ = CN) was treated with Me₂NH and the resulting I (R = Me₂N, R¹ = CN) treated with PhSO₃^–.NH₄⁺ to give I (R = Me₂N, R¹ = C(:NH)NH₂).PhSO₃H, which was cyclized with H₂C(CO₂Me)₂ to give the bipyrimidine II. II was chlorinated by POCl₃ and then treated with Me₂NH and Me₂NCH₂CH₂NH₂ to give the bipyrimidine III. In the experiment, the researchers used many compounds, for example, 2-Chloropyrimidine-4-carbonitrile (cas: 75833-38-4Quality Control of 2-Chloropyrimidine-4-carbonitrile).

2-Chloropyrimidine-4-carbonitrile (cas: 75833-38-4) belongs to pyrimidine derivatives. The pyrimidine ring system has wide occurrence in nature as substituted and ring fused compounds and derivatives. We all know its importance to life – pyrimidine and purine bases are included in the structure of DNA and RNA.Quality Control of 2-Chloropyrimidine-4-carbonitrile

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia