How is 6-Bromo-2,4-dichloroquinazoline (CAS: 102393-82-8) typically synthesized?

6-Bromo-2,4-dichloroquinazoline (CAS: 102393-82-8) is typically synthesized via a series of reactions including chlorination, bromination, and quinazoline formation. Common methods involve the use of chlorinating agents like thionyl chloride and brominating agents like bromine. The final step often involves coupling reactions, such as using the Wittig reaction or a Heck coupling, to introduce the bromine and chlorine substituents.