Yamaguchi, Hitoshi et al. published their research in Journal of Heterocyclic Chemistry in 1981 |CAS: 42518-42-3

The Article related to thienopyrimidine chloro dihydro reaction, quinazoline chloro dihydro reaction, imidazoquinazolinone, Heterocyclic Compounds (More Than One Hetero Atom): Pyrimidines and Quinazolines and other aspects.Formula: C8H6Cl2N2S

On January 31, 1981, Yamaguchi, Hitoshi; Ishikawa, Fumiyoshi published an article.Formula: C8H6Cl2N2S The title of the article was Synthesis and reactions of 2-chloro-3,4-dihydrothienopyrimidines and -quinazolines. And the article contained the following:

Reaction of 2,4-dichlorothienopyrimidines and -quinazolines with NaBH4 gave the corresponding 2-chloro-3,4-dihydro derivatives, e.g. I, II, and III (R = Me, R1 = H; R = R1 = Cl). Some nucleophilic substitutions of I afforded 2-substituted derivatives; reaction of III (R = Me, R1 = H; R = R1 = Cl) with BrCH2CO2Et yielded selectively the corresponding 3-substituted compounds, which were converted to imidazoquinazolinones IV. The experimental process involved the reaction of 2,4-Dichloro-5,6-dimethylthieno[2,3-d]pyrimidine(cas: 42518-42-3).Formula: C8H6Cl2N2S

The Article related to thienopyrimidine chloro dihydro reaction, quinazoline chloro dihydro reaction, imidazoquinazolinone, Heterocyclic Compounds (More Than One Hetero Atom): Pyrimidines and Quinazolines and other aspects.Formula: C8H6Cl2N2S

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia