Introducing Telescoping Process to Synthesis of a Key Intermediate of Drug Discoveries Using Design of Experiment

The 5-bromo-2-methylamino-8-methoxyquinazoline (1) is a key intermediate in our drug discoveries. Compound 1 bears a monomethylamino group at the 2-position of the quinazoline ring. This compound has been synthesized from 6-bromo-2-fluoro-3-methoxybenzaldehyde by a synthetic route including a total of four isolation processes in the medicinal chemistry laboratories. Our process chemistry laboratories successfully improved the original synthetic route by introducing the telescoping process. We successfully reduced the isolation processes from four to two processes by using information extracted through design of experiment. The total yield of compound 1 increased by 18%, while maintaining the purity of compound 1 of the original synthetic route. Accordingly, we contributed to the quick supply of compound 1 to the medicinal laboratories.